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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DiscontinuedOperationsAndDisposalGroupsAbstract" xlink:to="lab_us-gaap_DiscontinuedOperationsAndDisposalGroupsAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_ccc2b964-4ab7-4bb0-b2ab-eababd6ee4b8_terseLabel_en-US" xlink:label="lab_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Investment, Name</link:label>
    <link:label id="lab_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_label_en-US" xlink:label="lab_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Investment, Name [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:to="lab_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_PartnersCapitalIssuanceCosts_b7b6b311-e2a6-4202-9538-a4833b33a8e8_terseLabel_en-US" xlink:label="lab_smlp_PartnersCapitalIssuanceCosts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Issuance costs</link:label>
    <link:label id="lab_smlp_PartnersCapitalIssuanceCosts_label_en-US" xlink:label="lab_smlp_PartnersCapitalIssuanceCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Partners Capital, Issuance Costs</link:label>
    <link:label id="lab_smlp_PartnersCapitalIssuanceCosts_documentation_en-US" xlink:label="lab_smlp_PartnersCapitalIssuanceCosts" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Partners Capital, Issuance Costs</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_PartnersCapitalIssuanceCosts" xlink:href="smlp-20240331.xsd#smlp_PartnersCapitalIssuanceCosts"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_PartnersCapitalIssuanceCosts" xlink:to="lab_smlp_PartnersCapitalIssuanceCosts" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LossContingencyPendingClaimsNumber_8669cf26-31f3-4cad-b523-ef977cdf71b1_terseLabel_en-US" xlink:label="lab_us-gaap_LossContingencyPendingClaimsNumber" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Pending claims</link:label>
    <link:label id="lab_us-gaap_LossContingencyPendingClaimsNumber_label_en-US" xlink:label="lab_us-gaap_LossContingencyPendingClaimsNumber" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Loss Contingency, Pending Claims, Number</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyPendingClaimsNumber" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LossContingencyPendingClaimsNumber"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LossContingencyPendingClaimsNumber" xlink:to="lab_us-gaap_LossContingencyPendingClaimsNumber" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_DebtInstrumentCovenantMandatoryRedemptionPeriod_ad0c2ba8-0bb4-4840-be5b-84ae13ac8793_terseLabel_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantMandatoryRedemptionPeriod" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Mandatory redemption period</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantMandatoryRedemptionPeriod_label_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantMandatoryRedemptionPeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Mandatory Redemption Period</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantMandatoryRedemptionPeriod_documentation_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantMandatoryRedemptionPeriod" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Mandatory Redemption Period</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_DebtInstrumentCovenantMandatoryRedemptionPeriod" xlink:href="smlp-20240331.xsd#smlp_DebtInstrumentCovenantMandatoryRedemptionPeriod"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_DebtInstrumentCovenantMandatoryRedemptionPeriod" xlink:to="lab_smlp_DebtInstrumentCovenantMandatoryRedemptionPeriod" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CommitmentsAndContingencies_13fbcf86-5209-4cbb-97db-b478be43e2be_terseLabel_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingencies" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Commitments and contingencies (Note 14)</link:label>
    <link:label id="lab_us-gaap_CommitmentsAndContingencies_label_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingencies" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Commitments and Contingencies</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommitmentsAndContingencies" xlink:to="lab_us-gaap_CommitmentsAndContingencies" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DisaggregationOfRevenueLineItems_b68d60c1-a7fb-4543-a609-a59555d7bd12_terseLabel_en-US" xlink:label="lab_us-gaap_DisaggregationOfRevenueLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Disaggregation of Revenue [Line Items]</link:label>
    <link:label id="lab_us-gaap_DisaggregationOfRevenueLineItems_label_en-US" xlink:label="lab_us-gaap_DisaggregationOfRevenueLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disaggregation of Revenue [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems" xlink:to="lab_us-gaap_DisaggregationOfRevenueLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_ProfitLossExcludingSubsidiaryIncome_14ebe597-c905-4f0f-9681-e222ffaddae0_verboseLabel_en-US" xlink:label="lab_smlp_ProfitLossExcludingSubsidiaryIncome" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Net income (loss)</link:label>
    <link:label id="lab_smlp_ProfitLossExcludingSubsidiaryIncome_label_en-US" xlink:label="lab_smlp_ProfitLossExcludingSubsidiaryIncome" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Profit Loss Excluding Subsidiary Income</link:label>
    <link:label id="lab_smlp_ProfitLossExcludingSubsidiaryIncome_documentation_en-US" xlink:label="lab_smlp_ProfitLossExcludingSubsidiaryIncome" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Profit loss excluding subsidiary income.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_ProfitLossExcludingSubsidiaryIncome" xlink:href="smlp-20240331.xsd#smlp_ProfitLossExcludingSubsidiaryIncome"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_ProfitLossExcludingSubsidiaryIncome" xlink:to="lab_smlp_ProfitLossExcludingSubsidiaryIncome" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LineOfCreditFacilityLineItems_dd41eaf7-e328-457f-bf1a-1d4c491f6841_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Line of Credit Facility [Line Items]</link:label>
    <link:label id="lab_us-gaap_LineOfCreditFacilityLineItems_label_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Line of Credit Facility [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems" xlink:to="lab_us-gaap_LineOfCreditFacilityLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodThree_5319c6dd-dc79-455f-926a-04e690708307_terseLabel_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodThree" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt instrument, covenant, excess cash flow offer to purchase, period three</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodThree_label_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodThree" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Excess Cash Flow Offer To Purchase, Period Three</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodThree_documentation_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodThree" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Excess Cash Flow Offer To Purchase, Period Three</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodThree" xlink:href="smlp-20240331.xsd#smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodThree"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodThree" xlink:to="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodThree" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_652f734d-ad45-49a6-a9f1-ababfa68aae5_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInContractWithCustomerLiability" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Deferred revenue, net</link:label>
    <link:label id="lab_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInContractWithCustomerLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Increase (Decrease) in Contract with Customer, Liability</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerLiability"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability" xlink:to="lab_us-gaap_IncreaseDecreaseInContractWithCustomerLiability" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ConcentrationRiskLineItems_67f31e6f-e335-469f-9e4f-2ba96f9c3024_terseLabel_en-US" xlink:label="lab_us-gaap_ConcentrationRiskLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Concentration Risk [Line Items]</link:label>
    <link:label id="lab_us-gaap_ConcentrationRiskLineItems_label_en-US" xlink:label="lab_us-gaap_ConcentrationRiskLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Concentration Risk [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConcentrationRiskLineItems" xlink:to="lab_us-gaap_ConcentrationRiskLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_LimitedPartnerCommonUnitsMember_c77d3e75-c725-4d4c-bebb-94b3abdaac83_terseLabel_en-US" xlink:label="lab_smlp_LimitedPartnerCommonUnitsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Common Units</link:label>
    <link:label id="lab_smlp_LimitedPartnerCommonUnitsMember_label_en-US" xlink:label="lab_smlp_LimitedPartnerCommonUnitsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Limited Partner Common Units [Member]</link:label>
    <link:label id="lab_smlp_LimitedPartnerCommonUnitsMember_documentation_en-US" xlink:label="lab_smlp_LimitedPartnerCommonUnitsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Limited partner common units.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_LimitedPartnerCommonUnitsMember" xlink:href="smlp-20240331.xsd#smlp_LimitedPartnerCommonUnitsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_LimitedPartnerCommonUnitsMember" xlink:to="lab_smlp_LimitedPartnerCommonUnitsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_GasGatheringAndProcessingEquipmentMember_7d4cf061-ce76-4a49-b777-6d7e6711c982_terseLabel_en-US" xlink:label="lab_us-gaap_GasGatheringAndProcessingEquipmentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Gathering and processing systems and related equipment</link:label>
    <link:label id="lab_us-gaap_GasGatheringAndProcessingEquipmentMember_label_en-US" xlink:label="lab_us-gaap_GasGatheringAndProcessingEquipmentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Gas Gathering and Processing Equipment [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GasGatheringAndProcessingEquipmentMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GasGatheringAndProcessingEquipmentMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GasGatheringAndProcessingEquipmentMember" xlink:to="lab_us-gaap_GasGatheringAndProcessingEquipmentMember" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_SeniorNotesDue2026Member_733e70c8-7e56-4024-92fc-3fee8afdfadd_terseLabel_en-US" xlink:label="lab_smlp_SeniorNotesDue2026Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2026 Secured Notes</link:label>
    <link:label id="lab_smlp_SeniorNotesDue2026Member_label_en-US" xlink:label="lab_smlp_SeniorNotesDue2026Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Senior Notes Due 2026 [Member]</link:label>
    <link:label id="lab_smlp_SeniorNotesDue2026Member_documentation_en-US" xlink:label="lab_smlp_SeniorNotesDue2026Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Senior Notes Due 2026</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_SeniorNotesDue2026Member" xlink:href="smlp-20240331.xsd#smlp_SeniorNotesDue2026Member"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_SeniorNotesDue2026Member" xlink:to="lab_smlp_SeniorNotesDue2026Member" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccrualForEnvironmentalLossContingenciesPayments1_11f0ad60-ad07-4a75-a77b-1d73dfd7aa18_negatedLabel_en-US" xlink:label="lab_us-gaap_AccrualForEnvironmentalLossContingenciesPayments1" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Payments made</link:label>
    <link:label id="lab_us-gaap_AccrualForEnvironmentalLossContingenciesPayments1_label_en-US" xlink:label="lab_us-gaap_AccrualForEnvironmentalLossContingenciesPayments1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accrual for Environmental Loss Contingencies, Payments</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccrualForEnvironmentalLossContingenciesPayments1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccrualForEnvironmentalLossContingenciesPayments1"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccrualForEnvironmentalLossContingenciesPayments1" xlink:to="lab_us-gaap_AccrualForEnvironmentalLossContingenciesPayments1" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SubsequentEventTypeDomain_37d97bb3-0c01-49b1-b4cd-7f488dc14db4_terseLabel_en-US" xlink:label="lab_us-gaap_SubsequentEventTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Subsequent Event Type</link:label>
    <link:label id="lab_us-gaap_SubsequentEventTypeDomain_label_en-US" xlink:label="lab_us-gaap_SubsequentEventTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Subsequent Event Type [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventTypeDomain" xlink:to="lab_us-gaap_SubsequentEventTypeDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ProceedsFromDivestitureOfBusinesses_31fc1de0-80b6-4418-8d50-51da47cd80b4_verboseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromDivestitureOfBusinesses" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Proceeds from sale of business</link:label>
    <link:label id="lab_us-gaap_ProceedsFromDivestitureOfBusinesses_c2f8ed3a-a8d4-4bfc-acc2-9bd0c9f82850_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromDivestitureOfBusinesses" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Proceeds from divestiture of businesses</link:label>
    <link:label id="lab_us-gaap_ProceedsFromDivestitureOfBusinesses_label_en-US" xlink:label="lab_us-gaap_ProceedsFromDivestitureOfBusinesses" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Proceeds from Divestiture of Businesses</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromDivestitureOfBusinesses" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromDivestitureOfBusinesses"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromDivestitureOfBusinesses" xlink:to="lab_us-gaap_ProceedsFromDivestitureOfBusinesses" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_LandandLineFillMember_92127593-6433-46a5-a0da-ab2682584af8_terseLabel_en-US" xlink:label="lab_smlp_LandandLineFillMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Land and line fill</link:label>
    <link:label id="lab_smlp_LandandLineFillMember_label_en-US" xlink:label="lab_smlp_LandandLineFillMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Landand Line Fill [Member]</link:label>
    <link:label id="lab_smlp_LandandLineFillMember_documentation_en-US" xlink:label="lab_smlp_LandandLineFillMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Land and line fill.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_LandandLineFillMember" xlink:href="smlp-20240331.xsd#smlp_LandandLineFillMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_LandandLineFillMember" xlink:to="lab_smlp_LandandLineFillMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_44e311db-36b1-4dd4-80b0-7b0cf880a51c_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment [Table]</link:label>
    <link:label id="lab_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="lab_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccountsReceivableNetCurrent_9e00747b-e6d2-40b7-b7b6-9aa20bc39128_terseLabel_en-US" xlink:label="lab_us-gaap_AccountsReceivableNetCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accounts receivable</link:label>
    <link:label id="lab_us-gaap_AccountsReceivableNetCurrent_label_en-US" xlink:label="lab_us-gaap_AccountsReceivableNetCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accounts Receivable, after Allowance for Credit Loss, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccountsReceivableNetCurrent" xlink:to="lab_us-gaap_AccountsReceivableNetCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DistributionPayable_19f7ae5f-76f2-4476-82c1-cefa4ecb3d97_terseLabel_en-US" xlink:label="lab_us-gaap_DistributionPayable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Distribution payable</link:label>
    <link:label id="lab_us-gaap_DistributionPayable_label_en-US" xlink:label="lab_us-gaap_DistributionPayable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Distribution Payable</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DistributionPayable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DistributionPayable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DistributionPayable" xlink:to="lab_us-gaap_DistributionPayable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SupplementalCashFlowElementsAbstract_94978592-25c5-47b9-b7b8-bd387dedc7d0_terseLabel_en-US" xlink:label="lab_us-gaap_SupplementalCashFlowElementsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Supplemental Cash Flow Elements [Abstract]</link:label>
    <link:label id="lab_us-gaap_SupplementalCashFlowElementsAbstract_label_en-US" xlink:label="lab_us-gaap_SupplementalCashFlowElementsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Supplemental Cash Flow Elements [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplementalCashFlowElementsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SupplementalCashFlowElementsAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SupplementalCashFlowElementsAbstract" xlink:to="lab_us-gaap_SupplementalCashFlowElementsAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueInputsLevel3Member_7b4c8d66-1434-4f8a-8408-0e5548700cef_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueInputsLevel3Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value, Inputs, Level 3</link:label>
    <link:label id="lab_us-gaap_FairValueInputsLevel3Member_label_en-US" xlink:label="lab_us-gaap_FairValueInputsLevel3Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, Inputs, Level 3 [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueInputsLevel3Member" xlink:to="lab_us-gaap_FairValueInputsLevel3Member" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LineOfCreditMember_d85667b1-8028-4c60-a9e9-af152f7746e3_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Line of Credit</link:label>
    <link:label id="lab_us-gaap_LineOfCreditMember_label_en-US" xlink:label="lab_us-gaap_LineOfCreditMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Line of Credit [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LineOfCreditMember" xlink:to="lab_us-gaap_LineOfCreditMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccrualForEnvironmentalLossContingenciesRollForward_11d5d4bd-9050-464b-9d8e-f4a0f0e0b510_terseLabel_en-US" xlink:label="lab_us-gaap_AccrualForEnvironmentalLossContingenciesRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accrual for Environmental Loss Contingencies [Roll Forward]</link:label>
    <link:label id="lab_us-gaap_AccrualForEnvironmentalLossContingenciesRollForward_label_en-US" xlink:label="lab_us-gaap_AccrualForEnvironmentalLossContingenciesRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accrual for Environmental Loss Contingencies [Roll Forward]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccrualForEnvironmentalLossContingenciesRollForward" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccrualForEnvironmentalLossContingenciesRollForward"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccrualForEnvironmentalLossContingenciesRollForward" xlink:to="lab_us-gaap_AccrualForEnvironmentalLossContingenciesRollForward" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccruedEmployeeBenefitsCurrent_d9ec4747-0fe5-4c10-84b8-a73147ef42b4_terseLabel_en-US" xlink:label="lab_us-gaap_AccruedEmployeeBenefitsCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accrued compensation and employee benefits</link:label>
    <link:label id="lab_us-gaap_AccruedEmployeeBenefitsCurrent_label_en-US" xlink:label="lab_us-gaap_AccruedEmployeeBenefitsCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accrued Employee Benefits, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedEmployeeBenefitsCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccruedEmployeeBenefitsCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccruedEmployeeBenefitsCurrent" xlink:to="lab_us-gaap_AccruedEmployeeBenefitsCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_LitigationCaseAxis_36b62fa5-f800-457b-9c7e-e4756d391a29_terseLabel_en-US" xlink:label="lab_srt_LitigationCaseAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Litigation Case [Axis]</link:label>
    <link:label id="lab_srt_LitigationCaseAxis_label_en-US" xlink:label="lab_srt_LitigationCaseAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Litigation Case [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseAxis" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_LitigationCaseAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_LitigationCaseAxis" xlink:to="lab_srt_LitigationCaseAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_TradingSymbol_716382b8-d9ba-45f3-8ef3-73504fa9603d_terseLabel_en-US" xlink:label="lab_dei_TradingSymbol" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Trading Symbol</link:label>
    <link:label id="lab_dei_TradingSymbol_label_en-US" xlink:label="lab_dei_TradingSymbol" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Trading Symbol</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_TradingSymbol"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_TradingSymbol" xlink:to="lab_dei_TradingSymbol" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PaymentsToAcquireEquityMethodInvestments_d8df5559-d56c-4b0a-9a31-32cb9617e25e_negatedLabel_en-US" xlink:label="lab_us-gaap_PaymentsToAcquireEquityMethodInvestments" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Investment in Double E equity method investee</link:label>
    <link:label id="lab_us-gaap_PaymentsToAcquireEquityMethodInvestments_label_en-US" xlink:label="lab_us-gaap_PaymentsToAcquireEquityMethodInvestments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Payments to Acquire Equity Method Investments</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireEquityMethodInvestments" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsToAcquireEquityMethodInvestments"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsToAcquireEquityMethodInvestments" xlink:to="lab_us-gaap_PaymentsToAcquireEquityMethodInvestments" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NetIncomeLoss_bab0851b-f67a-40a8-9400-93ef6d9ccbf1_totalLabel_en-US" xlink:label="lab_us-gaap_NetIncomeLoss" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net income (loss) attributable to Summit Midstream Partners, LP</link:label>
    <link:label id="lab_us-gaap_NetIncomeLoss_cf411324-ae0b-487d-b732-0289bf8921d9_terseLabel_en-US" xlink:label="lab_us-gaap_NetIncomeLoss" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Net income (loss) attributable to Summit Midstream Partners, LP</link:label>
    <link:label id="lab_us-gaap_NetIncomeLoss_label_en-US" xlink:label="lab_us-gaap_NetIncomeLoss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net Income (Loss)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLoss"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetIncomeLoss" xlink:to="lab_us-gaap_NetIncomeLoss" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LiabilitiesCurrent_47583df0-88ad-4318-98b7-4107f6778bbf_totalLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total current liabilities</link:label>
    <link:label id="lab_us-gaap_LiabilitiesCurrent_label_en-US" xlink:label="lab_us-gaap_LiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Liabilities, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesCurrent" xlink:to="lab_us-gaap_LiabilitiesCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember_0d62370b-9bf3-4886-8fbd-9eaafc78687d_terseLabel_en-US" xlink:label="lab_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember"/>
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    <link:label id="lab_us-gaap_DerivativeContractTypeDomain_8870cc6b-03fb-4bdb-bbe2-15bff32502da_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeContractTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Derivative Contract</link:label>
    <link:label id="lab_us-gaap_DerivativeContractTypeDomain_label_en-US" xlink:label="lab_us-gaap_DerivativeContractTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative Contract [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeContractTypeDomain" xlink:to="lab_us-gaap_DerivativeContractTypeDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueDisclosuresAbstract_127a250b-3b78-48ab-aba1-b7fd10d099af_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueDisclosuresAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value Disclosures [Abstract]</link:label>
    <link:label id="lab_us-gaap_FairValueDisclosuresAbstract_label_en-US" xlink:label="lab_us-gaap_FairValueDisclosuresAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value Disclosures [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosuresAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueDisclosuresAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueDisclosuresAbstract" xlink:to="lab_us-gaap_FairValueDisclosuresAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_InterestPayableCurrent_eb1c5a2d-f059-4016-b39c-20a4ec96fc05_terseLabel_en-US" xlink:label="lab_us-gaap_InterestPayableCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accrued interest</link:label>
    <link:label id="lab_us-gaap_InterestPayableCurrent_label_en-US" xlink:label="lab_us-gaap_InterestPayableCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Interest Payable, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestPayableCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestPayableCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestPayableCurrent" xlink:to="lab_us-gaap_InterestPayableCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_TermLoanCreditFacilityMember_8b62b0c9-df22-44ea-8861-dba75f92a719_terseLabel_en-US" xlink:label="lab_smlp_TermLoanCreditFacilityMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Term Loan Credit Facility</link:label>
    <link:label id="lab_smlp_TermLoanCreditFacilityMember_label_en-US" xlink:label="lab_smlp_TermLoanCreditFacilityMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Term Loan Credit Facility [Member]</link:label>
    <link:label id="lab_smlp_TermLoanCreditFacilityMember_documentation_en-US" xlink:label="lab_smlp_TermLoanCreditFacilityMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Term loan credit facility.</link:label>
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    <link:label id="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract_8fd7cc8f-1d01-4c08-a368-522406a93b18_terseLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">LIABILITIES AND CAPITAL</link:label>
    <link:label id="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract_label_en-US" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Liabilities and Equity [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
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    <link:label id="lab_us-gaap_DebtInstrumentRedemptionPeriodAxis_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentRedemptionPeriodAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Redemption, Period [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentRedemptionPeriodAxis"/>
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    <link:label id="lab_us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_ca09916e-d000-4aad-b9e0-fc6640fbfebd_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Earnings Per Share, Basic and Diluted</link:label>
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    <link:label id="lab_us-gaap_CostOfGoodsAndServicesSold_151685cc-ba98-45ea-b7d2-090b4b993d8b_terseLabel_en-US" xlink:label="lab_us-gaap_CostOfGoodsAndServicesSold" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Cost of natural gas and NGLs</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
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    <link:label id="lab_us-gaap_ProceedsFromSaleOfProductiveAssets_35851ad2-cf20-44cd-b528-ae677b45ba04_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromSaleOfProductiveAssets" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Proceeds from asset sale</link:label>
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    <link:label id="lab_smlp_CreditAgreementMember_d057de93-eb6a-49f2-b2be-e70177aae4b3_terseLabel_en-US" xlink:label="lab_smlp_CreditAgreementMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Credit Agreement</link:label>
    <link:label id="lab_smlp_CreditAgreementMember_label_en-US" xlink:label="lab_smlp_CreditAgreementMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Credit Agreement [Member]</link:label>
    <link:label id="lab_smlp_CreditAgreementMember_documentation_en-US" xlink:label="lab_smlp_CreditAgreementMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Credit agreement.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_CreditAgreementMember" xlink:href="smlp-20240331.xsd#smlp_CreditAgreementMember"/>
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    <link:label id="lab_us-gaap_SignificantAccountingPoliciesTextBlock_b436ee6f-4057-493c-be15-88bd9a8986ed_terseLabel_en-US" xlink:label="lab_us-gaap_SignificantAccountingPoliciesTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND RECENTLY ISSUED ACCOUNTING STANDARDS APPLICABLE TO THE PARTNERSHIP</link:label>
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    <link:label id="lab_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_3e866524-1d1e-4c5b-9134-273fcde9c538_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Borrowing base capacity</link:label>
    <link:label id="lab_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_label_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Line of Credit Facility, Current Borrowing Capacity</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity"/>
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    <link:label id="lab_us-gaap_CarryingReportedAmountFairValueDisclosureMember_8eb42db1-8dbb-43dc-af3f-db4ba4430907_terseLabel_en-US" xlink:label="lab_us-gaap_CarryingReportedAmountFairValueDisclosureMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Carrying Value</link:label>
    <link:label id="lab_us-gaap_CarryingReportedAmountFairValueDisclosureMember_label_en-US" xlink:label="lab_us-gaap_CarryingReportedAmountFairValueDisclosureMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Reported Value Measurement [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember" xlink:to="lab_us-gaap_CarryingReportedAmountFairValueDisclosureMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_UtilitiesOperatingExpenseMaintenanceAndOperations_76f86728-1941-4b0b-9cc5-f9b9aabbb5b2_terseLabel_en-US" xlink:label="lab_us-gaap_UtilitiesOperatingExpenseMaintenanceAndOperations" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Operation and maintenance</link:label>
    <link:label id="lab_us-gaap_UtilitiesOperatingExpenseMaintenanceAndOperations_label_en-US" xlink:label="lab_us-gaap_UtilitiesOperatingExpenseMaintenanceAndOperations" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Utilities Operating Expense, Maintenance and Operations</link:label>
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    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentTextBlock_3c8d4333-3b5d-47e0-b338-713ec7c5255b_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Property, Plant and Equipment</link:label>
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    <link:label id="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodOne_87324750-d144-4bd4-a2f8-7bfb2c8ee5ff_terseLabel_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodOne" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt instrument, covenant, excess cash flow offer to purchase, period one</link:label>
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    <link:label id="lab_smlp_DebtInstrumentCovenantMaximumAmountOutstandingForMaturity_b5724963-54f2-4c51-8f18-1f1012a89a83_terseLabel_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantMaximumAmountOutstandingForMaturity" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Maximum amount of debt outstanding for maturity to occur</link:label>
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    <link:label id="lab_us-gaap_OtherCapitalizedPropertyPlantAndEquipmentMember_99e3921d-a3ee-4c44-9d16-c8358842404e_terseLabel_en-US" xlink:label="lab_us-gaap_OtherCapitalizedPropertyPlantAndEquipmentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other</link:label>
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    <link:label id="lab_us-gaap_LineOfCreditFacilityTable_fbd45f52-2ddb-4a1f-b238-0d4be6485616_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Line of Credit Facility [Table]</link:label>
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    <link:label id="lab_smlp_GainLossOnSaleOfAssetsNet_documentation_en-US" xlink:label="lab_smlp_GainLossOnSaleOfAssetsNet" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Gain (Loss) on Sale Of Assets, Net</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_GainLossOnSaleOfAssetsNet" xlink:href="smlp-20240331.xsd#smlp_GainLossOnSaleOfAssetsNet"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_GainLossOnSaleOfAssetsNet" xlink:to="lab_smlp_GainLossOnSaleOfAssetsNet" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_NaturalGasNGLAndCondensateSalesMember_19ed34eb-eb6d-4e1e-a491-fbba077d86b8_terseLabel_en-US" xlink:label="lab_smlp_NaturalGasNGLAndCondensateSalesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Natural gas, NGLs and condensate sales</link:label>
    <link:label id="lab_smlp_NaturalGasNGLAndCondensateSalesMember_label_en-US" xlink:label="lab_smlp_NaturalGasNGLAndCondensateSalesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Natural Gas N G L And Condensate Sales [Member]</link:label>
    <link:label id="lab_smlp_NaturalGasNGLAndCondensateSalesMember_documentation_en-US" xlink:label="lab_smlp_NaturalGasNGLAndCondensateSalesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Natural gas, NGLs and condensate sales.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_NaturalGasNGLAndCondensateSalesMember" xlink:href="smlp-20240331.xsd#smlp_NaturalGasNGLAndCondensateSalesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_NaturalGasNGLAndCondensateSalesMember" xlink:to="lab_smlp_NaturalGasNGLAndCondensateSalesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_ProductsAndServicesDomain_d0e8a515-9e20-4dcf-afd2-2e6bce9c764c_terseLabel_en-US" xlink:label="lab_srt_ProductsAndServicesDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Product and Service</link:label>
    <link:label id="lab_srt_ProductsAndServicesDomain_label_en-US" xlink:label="lab_srt_ProductsAndServicesDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Product and Service [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductsAndServicesDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_ProductsAndServicesDomain" xlink:to="lab_srt_ProductsAndServicesDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_0dac9590-f738-4934-b5af-028b4be08a93_terseLabel_en-US" xlink:label="lab_us-gaap_TemporaryEquityCarryingAmountAttributableToParent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Subsidiary Series A Preferred Units (93,039 units issued and outstanding at March&#160;31, 2024 and December&#160;31, 2023)</link:label>
    <link:label id="lab_us-gaap_TemporaryEquityCarryingAmountAttributableToParent_label_en-US" xlink:label="lab_us-gaap_TemporaryEquityCarryingAmountAttributableToParent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Temporary Equity, Carrying Amount, Attributable to Parent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityCarryingAmountAttributableToParent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_TemporaryEquityCarryingAmountAttributableToParent" xlink:to="lab_us-gaap_TemporaryEquityCarryingAmountAttributableToParent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StandbyLettersOfCreditMember_18ae5b24-36b4-41a8-932b-0c6bc203b47d_terseLabel_en-US" xlink:label="lab_us-gaap_StandbyLettersOfCreditMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Standby Letters of Credit</link:label>
    <link:label id="lab_us-gaap_StandbyLettersOfCreditMember_label_en-US" xlink:label="lab_us-gaap_StandbyLettersOfCreditMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Standby Letters of Credit [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StandbyLettersOfCreditMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StandbyLettersOfCreditMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StandbyLettersOfCreditMember" xlink:to="lab_us-gaap_StandbyLettersOfCreditMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_b7bbc883-e61b-460c-be27-84511e6cec5b_terseLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Cash flows from investing activities:</link:label>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net Cash Provided by (Used in) Investing Activities [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_DebtInstrumentCovenantUnrestrictedCashThreshold_ad236cf4-a1c5-465e-80c3-7a9ff27c0312_terseLabel_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantUnrestrictedCashThreshold" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt instrument, covenant, unrestricted cash threshold</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantUnrestrictedCashThreshold_label_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantUnrestrictedCashThreshold" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Unrestricted Cash Threshold</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantUnrestrictedCashThreshold_documentation_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantUnrestrictedCashThreshold" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Unrestricted Cash Threshold</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_DebtInstrumentCovenantUnrestrictedCashThreshold" xlink:href="smlp-20240331.xsd#smlp_DebtInstrumentCovenantUnrestrictedCashThreshold"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_DebtInstrumentCovenantUnrestrictedCashThreshold" xlink:to="lab_smlp_DebtInstrumentCovenantUnrestrictedCashThreshold" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_ChangeInContractWithCustomerLiabilityNoncurrentRollForward_678fde7e-adc4-4693-befe-646fde80b409_terseLabel_en-US" xlink:label="lab_smlp_ChangeInContractWithCustomerLiabilityNoncurrentRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Change in Contract with Customer, Liability, Noncurrent [Roll Forward]</link:label>
    <link:label id="lab_smlp_ChangeInContractWithCustomerLiabilityNoncurrentRollForward_label_en-US" xlink:label="lab_smlp_ChangeInContractWithCustomerLiabilityNoncurrentRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Change in Contract with Customer, Liability, Noncurrent [Roll Forward]</link:label>
    <link:label id="lab_smlp_ChangeInContractWithCustomerLiabilityNoncurrentRollForward_documentation_en-US" xlink:label="lab_smlp_ChangeInContractWithCustomerLiabilityNoncurrentRollForward" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Change in Contract with Customer, Liability, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_ChangeInContractWithCustomerLiabilityNoncurrentRollForward" xlink:href="smlp-20240331.xsd#smlp_ChangeInContractWithCustomerLiabilityNoncurrentRollForward"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_ChangeInContractWithCustomerLiabilityNoncurrentRollForward" xlink:to="lab_smlp_ChangeInContractWithCustomerLiabilityNoncurrentRollForward" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NotesPayableFairValueDisclosure_6d5aeeb9-19ac-40ea-8a9f-804c14f0a7ac_terseLabel_en-US" xlink:label="lab_us-gaap_NotesPayableFairValueDisclosure" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Senior notes</link:label>
    <link:label id="lab_us-gaap_NotesPayableFairValueDisclosure_label_en-US" xlink:label="lab_us-gaap_NotesPayableFairValueDisclosure" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Notes Payable, Fair Value Disclosure</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesPayableFairValueDisclosure" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NotesPayableFairValueDisclosure"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NotesPayableFairValueDisclosure" xlink:to="lab_us-gaap_NotesPayableFairValueDisclosure" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_BusinessCombinationAcquisitionRelatedCosts_f367f85f-5546-4c82-9b1e-7ead52ff4be0_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Transaction costs</link:label>
    <link:label id="lab_us-gaap_BusinessCombinationAcquisitionRelatedCosts_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Business Combination, Acquisition Related Costs</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:to="lab_us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AwardTypeAxis_ce9194cb-baef-4207-9650-0ae6809af72a_terseLabel_en-US" xlink:label="lab_us-gaap_AwardTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Award Type</link:label>
    <link:label id="lab_us-gaap_AwardTypeAxis_label_en-US" xlink:label="lab_us-gaap_AwardTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Award Type [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AwardTypeAxis" xlink:to="lab_us-gaap_AwardTypeAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_443210b1-ec84-474d-a816-44e24edac9c6_terseLabel_en-US" xlink:label="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Nonvested anti-dilutive phantom units excluded from the calculation of diluted EPU (in shares)</link:label>
    <link:label id="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_label_en-US" xlink:label="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:to="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_02a3cb79-98d3-4681-bd3e-00442300da09_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Granted units (in shares)</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PlanNameDomain_a80bdd61-770c-4dfc-8265-1fc90b22ba8c_terseLabel_en-US" xlink:label="lab_us-gaap_PlanNameDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Plan Name</link:label>
    <link:label id="lab_us-gaap_PlanNameDomain_label_en-US" xlink:label="lab_us-gaap_PlanNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Plan Name [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PlanNameDomain" xlink:to="lab_us-gaap_PlanNameDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_DocumentQuarterlyReport_1e352a14-5b67-4316-a183-dd065b10ea1e_terseLabel_en-US" xlink:label="lab_dei_DocumentQuarterlyReport" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Document Quarterly Report</link:label>
    <link:label id="lab_dei_DocumentQuarterlyReport_label_en-US" xlink:label="lab_dei_DocumentQuarterlyReport" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Quarterly Report</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentQuarterlyReport" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentQuarterlyReport"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentQuarterlyReport" xlink:to="lab_dei_DocumentQuarterlyReport" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_LongTermIncentivePlanMember_580004fa-5a75-4a94-8f8a-4043fd3723e9_terseLabel_en-US" xlink:label="lab_smlp_LongTermIncentivePlanMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">SMLP LTIP</link:label>
    <link:label id="lab_smlp_LongTermIncentivePlanMember_label_en-US" xlink:label="lab_smlp_LongTermIncentivePlanMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long Term Incentive Plan [Member]</link:label>
    <link:label id="lab_smlp_LongTermIncentivePlanMember_documentation_en-US" xlink:label="lab_smlp_LongTermIncentivePlanMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Long-term incentive plan.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_LongTermIncentivePlanMember" xlink:href="smlp-20240331.xsd#smlp_LongTermIncentivePlanMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_LongTermIncentivePlanMember" xlink:to="lab_smlp_LongTermIncentivePlanMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NoncashInvestingAndFinancingItemsAbstract_7de75f0f-f5dc-481a-bb7d-cbcc37d4bf8b_terseLabel_en-US" xlink:label="lab_us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Noncash investing and financing activities:</link:label>
    <link:label id="lab_us-gaap_NoncashInvestingAndFinancingItemsAbstract_label_en-US" xlink:label="lab_us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Noncash Investing and Financing Items [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NoncashInvestingAndFinancingItemsAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="lab_us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_InterestExpense_818905c3-ea05-4fd7-877e-ea92a47e5b7a_negatedLabel_en-US" xlink:label="lab_us-gaap_InterestExpense" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Interest expense</link:label>
    <link:label id="lab_us-gaap_InterestExpense_a68f1c12-54d8-4e76-a8b5-71cdf566d62d_terseLabel_en-US" xlink:label="lab_us-gaap_InterestExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Interest expense</link:label>
    <link:label id="lab_us-gaap_InterestExpense_label_en-US" xlink:label="lab_us-gaap_InterestExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Interest Expense</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestExpense"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestExpense" xlink:to="lab_us-gaap_InterestExpense" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_ReconciliationOfNetIncomeToEBITDAAdditionsAbstract_6ba9c121-5043-41d0-8f9c-cf6b927e38b9_terseLabel_en-US" xlink:label="lab_smlp_ReconciliationOfNetIncomeToEBITDAAdditionsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Add:</link:label>
    <link:label id="lab_smlp_ReconciliationOfNetIncomeToEBITDAAdditionsAbstract_label_en-US" xlink:label="lab_smlp_ReconciliationOfNetIncomeToEBITDAAdditionsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Reconciliation Of Net Income To E B I T D A Additions [Abstract]</link:label>
    <link:label id="lab_smlp_ReconciliationOfNetIncomeToEBITDAAdditionsAbstract_documentation_en-US" xlink:label="lab_smlp_ReconciliationOfNetIncomeToEBITDAAdditionsAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Reconciliation of net Income to EBITDA, additions.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_ReconciliationOfNetIncomeToEBITDAAdditionsAbstract" xlink:href="smlp-20240331.xsd#smlp_ReconciliationOfNetIncomeToEBITDAAdditionsAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_ReconciliationOfNetIncomeToEBITDAAdditionsAbstract" xlink:to="lab_smlp_ReconciliationOfNetIncomeToEBITDAAdditionsAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CapitalExpendituresIncurredButNotYetPaid_7b546c8e-9427-4274-b7fd-815420d7976c_terseLabel_en-US" xlink:label="lab_us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Capital expenditures in trade accounts payable (period-end accruals)</link:label>
    <link:label id="lab_us-gaap_CapitalExpendituresIncurredButNotYetPaid_label_en-US" xlink:label="lab_us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Capital Expenditures Incurred but Not yet Paid</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CapitalExpendituresIncurredButNotYetPaid"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:to="lab_us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_CondensedFinancialStatementsCaptionsLineItems_c527e068-af39-4876-a650-0be23530dc55_terseLabel_en-US" xlink:label="lab_srt_CondensedFinancialStatementsCaptionsLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Condensed Financial Statements, Captions [Line Items]</link:label>
    <link:label id="lab_srt_CondensedFinancialStatementsCaptionsLineItems_label_en-US" xlink:label="lab_srt_CondensedFinancialStatementsCaptionsLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Condensed Financial Statements, Captions [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CondensedFinancialStatementsCaptionsLineItems" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CondensedFinancialStatementsCaptionsLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems" xlink:to="lab_srt_CondensedFinancialStatementsCaptionsLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_ccbae74b-d01a-4061-bcc8-903f27a5c351_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value Hierarchy and NAV</link:label>
    <link:label id="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_label_en-US" xlink:label="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value Hierarchy and NAV [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentGross_f2d7ee4d-38fb-43b6-a0e5-e8129ea96674_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentGross" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Total</link:label>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentGross_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentGross" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment, Gross</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentGross" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentGross" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_DisposalGroupIncludingDiscontinuedOperationsNetBookValue_c648fc9a-fee8-469b-aebd-953c58c66aec_terseLabel_en-US" xlink:label="lab_smlp_DisposalGroupIncludingDiscontinuedOperationsNetBookValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Net book value of assets and liabilities divested</link:label>
    <link:label id="lab_smlp_DisposalGroupIncludingDiscontinuedOperationsNetBookValue_label_en-US" xlink:label="lab_smlp_DisposalGroupIncludingDiscontinuedOperationsNetBookValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operations, Net Book Value</link:label>
    <link:label id="lab_smlp_DisposalGroupIncludingDiscontinuedOperationsNetBookValue_documentation_en-US" xlink:label="lab_smlp_DisposalGroupIncludingDiscontinuedOperationsNetBookValue" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Disposal Group, Including Discontinued Operations, Net Book Value</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_DisposalGroupIncludingDiscontinuedOperationsNetBookValue" xlink:href="smlp-20240331.xsd#smlp_DisposalGroupIncludingDiscontinuedOperationsNetBookValue"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_DisposalGroupIncludingDiscontinuedOperationsNetBookValue" xlink:to="lab_smlp_DisposalGroupIncludingDiscontinuedOperationsNetBookValue" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_UseOfEstimates_849dcbc9-27a6-4e58-a1d7-5926c9c75c9d_terseLabel_en-US" xlink:label="lab_us-gaap_UseOfEstimates" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Use of Estimates</link:label>
    <link:label id="lab_us-gaap_UseOfEstimates_label_en-US" xlink:label="lab_us-gaap_UseOfEstimates" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Use of Estimates, Policy [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UseOfEstimates" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_UseOfEstimates"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_UseOfEstimates" xlink:to="lab_us-gaap_UseOfEstimates" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DistributionMadeToLimitedPartnerCashDistributionsDeclared_ba0b9cf1-6b87-4a70-9697-a7a841ffe9b5_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_DistributionMadeToLimitedPartnerCashDistributionsDeclared" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Cash distribution (includes a $1.6 million distribution payable as of March&#160;31, 2024)</link:label>
    <link:label id="lab_us-gaap_DistributionMadeToLimitedPartnerCashDistributionsDeclared_label_en-US" xlink:label="lab_us-gaap_DistributionMadeToLimitedPartnerCashDistributionsDeclared" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Distribution Made to Limited Partner, Cash Distributions Declared</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DistributionMadeToLimitedPartnerCashDistributionsDeclared" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DistributionMadeToLimitedPartnerCashDistributionsDeclared"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DistributionMadeToLimitedPartnerCashDistributionsDeclared" xlink:to="lab_us-gaap_DistributionMadeToLimitedPartnerCashDistributionsDeclared" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NoncontrollingInterestInNetIncomeLossPreferredUnitHoldersRedeemable_333d33d4-0d4f-4b1f-9774-2c18c1ed3d12_verboseLabel_en-US" xlink:label="lab_us-gaap_NoncontrollingInterestInNetIncomeLossPreferredUnitHoldersRedeemable" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Less: net income attributable to Series A Preferred Units</link:label>
    <link:label id="lab_us-gaap_NoncontrollingInterestInNetIncomeLossPreferredUnitHoldersRedeemable_07ca82c9-2319-4741-95ba-86b80b95575b_terseLabel_en-US" xlink:label="lab_us-gaap_NoncontrollingInterestInNetIncomeLossPreferredUnitHoldersRedeemable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Less: net income attributable to Series A Preferred Units</link:label>
    <link:label id="lab_us-gaap_NoncontrollingInterestInNetIncomeLossPreferredUnitHoldersRedeemable_label_en-US" xlink:label="lab_us-gaap_NoncontrollingInterestInNetIncomeLossPreferredUnitHoldersRedeemable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Noncontrolling Interest in Net Income (Loss) Preferred Unit Holders, Redeemable</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestInNetIncomeLossPreferredUnitHoldersRedeemable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NoncontrollingInterestInNetIncomeLossPreferredUnitHoldersRedeemable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NoncontrollingInterestInNetIncomeLossPreferredUnitHoldersRedeemable" xlink:to="lab_us-gaap_NoncontrollingInterestInNetIncomeLossPreferredUnitHoldersRedeemable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LongtermDebtTypeDomain_d344db2f-ecc3-409d-ad1d-e5dacad8c663_terseLabel_en-US" xlink:label="lab_us-gaap_LongtermDebtTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Long-term Debt, Type</link:label>
    <link:label id="lab_us-gaap_LongtermDebtTypeDomain_label_en-US" xlink:label="lab_us-gaap_LongtermDebtTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Debt, Type [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongtermDebtTypeDomain" xlink:to="lab_us-gaap_LongtermDebtTypeDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_PermianTransmissionTermLoanAnd2026SecuredNotesMember_be7bebc9-2efd-47c8-b7e9-ff9e756e8d88_terseLabel_en-US" xlink:label="lab_smlp_PermianTransmissionTermLoanAnd2026SecuredNotesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Permian Transmission Term Loan and 2026 Secured Notes</link:label>
    <link:label id="lab_smlp_PermianTransmissionTermLoanAnd2026SecuredNotesMember_label_en-US" xlink:label="lab_smlp_PermianTransmissionTermLoanAnd2026SecuredNotesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Permian Transmission Term Loan and 2026 Secured Notes [Member]</link:label>
    <link:label id="lab_smlp_PermianTransmissionTermLoanAnd2026SecuredNotesMember_documentation_en-US" xlink:label="lab_smlp_PermianTransmissionTermLoanAnd2026SecuredNotesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Permian Transmission Term Loan and 2026 Secured Notes</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_PermianTransmissionTermLoanAnd2026SecuredNotesMember" xlink:href="smlp-20240331.xsd#smlp_PermianTransmissionTermLoanAnd2026SecuredNotesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_PermianTransmissionTermLoanAnd2026SecuredNotesMember" xlink:to="lab_smlp_PermianTransmissionTermLoanAnd2026SecuredNotesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_EntityFileNumber_feb2485f-c30a-431e-b946-3c9c3556ed35_terseLabel_en-US" xlink:label="lab_dei_EntityFileNumber" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Entity File Number</link:label>
    <link:label id="lab_dei_EntityFileNumber_label_en-US" xlink:label="lab_dei_EntityFileNumber" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity File Number</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityFileNumber"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityFileNumber" xlink:to="lab_dei_EntityFileNumber" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LossContingenciesTable_77b37837-9531-4635-a48f-3aa5c24f38ad_terseLabel_en-US" xlink:label="lab_us-gaap_LossContingenciesTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Loss Contingencies [Table]</link:label>
    <link:label id="lab_us-gaap_LossContingenciesTable_label_en-US" xlink:label="lab_us-gaap_LossContingenciesTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Loss Contingencies [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LossContingenciesTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LossContingenciesTable" xlink:to="lab_us-gaap_LossContingenciesTable" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_ContractWithCustomerLiabilityNoncurrentAdditions_3e6387c4-4988-49e8-8823-949a576da5c2_terseLabel_en-US" xlink:label="lab_smlp_ContractWithCustomerLiabilityNoncurrentAdditions" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Add: additions</link:label>
    <link:label id="lab_smlp_ContractWithCustomerLiabilityNoncurrentAdditions_label_en-US" xlink:label="lab_smlp_ContractWithCustomerLiabilityNoncurrentAdditions" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Contract With Customer Liability, Noncurrent, Additions</link:label>
    <link:label id="lab_smlp_ContractWithCustomerLiabilityNoncurrentAdditions_documentation_en-US" xlink:label="lab_smlp_ContractWithCustomerLiabilityNoncurrentAdditions" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Contract with customer liability noncurrent additions.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_ContractWithCustomerLiabilityNoncurrentAdditions" xlink:href="smlp-20240331.xsd#smlp_ContractWithCustomerLiabilityNoncurrentAdditions"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_ContractWithCustomerLiabilityNoncurrentAdditions" xlink:to="lab_smlp_ContractWithCustomerLiabilityNoncurrentAdditions" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_c74523ac-bc25-4bff-a877-5f410e95dcf6_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2027</link:label>
    <link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_label_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Debt, Maturity, Year Three</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:to="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_EntityShellCompany_2d06332e-64a4-4fd5-829b-4231e6bb8f3c_terseLabel_en-US" xlink:label="lab_dei_EntityShellCompany" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Entity Shell Company</link:label>
    <link:label id="lab_dei_EntityShellCompany_label_en-US" xlink:label="lab_dei_EntityShellCompany" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Shell Company</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityShellCompany"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityShellCompany" xlink:to="lab_dei_EntityShellCompany" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_BusinessAcquisitionAcquireeDomain_4023adc9-63a5-47ff-9452-0345c2b76787_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Business Acquisition, Acquiree</link:label>
    <link:label id="lab_us-gaap_BusinessAcquisitionAcquireeDomain_label_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Business Acquisition, Acquiree [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="lab_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentLineItems_04ef2e68-ee8b-454c-b2ae-32d0a4abf522_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment [Line Items]</link:label>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentLineItems_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_358d98f7-a493-466f-a591-ca5ff3adcc9e_terseLabel_en-US" xlink:label="lab_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accounting standards recently implemented and New accounting standards not yet implemented</link:label>
    <link:label id="lab_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">New Accounting Pronouncements, Policy [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:to="lab_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_RepurchaseAgreementCounterpartyNameDomain_59132d8c-0988-4ffe-8ea9-3e3150036913_terseLabel_en-US" xlink:label="lab_srt_RepurchaseAgreementCounterpartyNameDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Counterparty Name [Domain]</link:label>
    <link:label id="lab_srt_RepurchaseAgreementCounterpartyNameDomain_label_en-US" xlink:label="lab_srt_RepurchaseAgreementCounterpartyNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Counterparty Name [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain" xlink:to="lab_srt_RepurchaseAgreementCounterpartyNameDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_622b9feb-c1e6-40ff-b3af-6e9f8437b5d0_periodStartLabel_en-US" xlink:label="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Cash, cash equivalents and restricted cash, beginning of period</link:label>
    <link:label id="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_80336727-131a-42d6-a829-76880cf77e60_periodEndLabel_en-US" xlink:label="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Cash, cash equivalents and restricted cash, end of period</link:label>
    <link:label id="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_label_en-US" xlink:label="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:to="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LineOfCreditFacilityCommitmentFeePercentage_5b83583e-1525-454a-a9be-7ebe33343241_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Commitment fee (as a percent)</link:label>
    <link:label id="lab_us-gaap_LineOfCreditFacilityCommitmentFeePercentage_label_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Line of Credit Facility, Commitment Fee Percentage</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityCommitmentFeePercentage"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:to="lab_us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ContractWithCustomerLiabilityCurrent_2ae5b488-8ecb-42a4-bad4-61d5b63c2afe_terseLabel_en-US" xlink:label="lab_us-gaap_ContractWithCustomerLiabilityCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Deferred revenue</link:label>
    <link:label id="lab_us-gaap_ContractWithCustomerLiabilityCurrent_eed99b1a-c283-4128-ad98-e1c8ee41b67c_periodStartLabel_en-US" xlink:label="lab_us-gaap_ContractWithCustomerLiabilityCurrent" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Current deferred revenue, beginning balance</link:label>
    <link:label id="lab_us-gaap_ContractWithCustomerLiabilityCurrent_684e4cde-99ae-4e1d-bc38-68c36ca2a475_periodEndLabel_en-US" xlink:label="lab_us-gaap_ContractWithCustomerLiabilityCurrent" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Current deferred revenue, ending balance</link:label>
    <link:label id="lab_us-gaap_ContractWithCustomerLiabilityCurrent_label_en-US" xlink:label="lab_us-gaap_ContractWithCustomerLiabilityCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Contract with Customer, Liability, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractWithCustomerLiabilityCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ContractWithCustomerLiabilityCurrent" xlink:to="lab_us-gaap_ContractWithCustomerLiabilityCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_SecurityExchangeName_314f90bf-987f-4073-9d1f-0712c9ee4429_terseLabel_en-US" xlink:label="lab_dei_SecurityExchangeName" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Security Exchange Name</link:label>
    <link:label id="lab_dei_SecurityExchangeName_label_en-US" xlink:label="lab_dei_SecurityExchangeName" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Security Exchange Name</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_SecurityExchangeName"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_SecurityExchangeName" xlink:to="lab_dei_SecurityExchangeName" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PartnersCapitalAccountUnitBasedCompensation_e477f12e-e530-4064-b077-ba1807b33826_terseLabel_en-US" xlink:label="lab_us-gaap_PartnersCapitalAccountUnitBasedCompensation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Unit-based compensation</link:label>
    <link:label id="lab_us-gaap_PartnersCapitalAccountUnitBasedCompensation_label_en-US" xlink:label="lab_us-gaap_PartnersCapitalAccountUnitBasedCompensation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Partners' Capital Account, Unit-Based Payment Arrangement, Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PartnersCapitalAccountUnitBasedCompensation" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PartnersCapitalAccountUnitBasedCompensation"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PartnersCapitalAccountUnitBasedCompensation" xlink:to="lab_us-gaap_PartnersCapitalAccountUnitBasedCompensation" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LongTermDebt_3c61b0de-2f5b-4035-aad7-8f2a1e801a8c_totalLabel_en-US" xlink:label="lab_us-gaap_LongTermDebt" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total debt, net of unamortized debt discount and debt issuance costs</link:label>
    <link:label id="lab_us-gaap_LongTermDebt_label_en-US" xlink:label="lab_us-gaap_LongTermDebt" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Debt</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebt"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebt" xlink:to="lab_us-gaap_LongTermDebt" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_BarnettShaleSegmentMember_a875c0ca-6d96-43ac-8897-225ab34eaafc_terseLabel_en-US" xlink:label="lab_smlp_BarnettShaleSegmentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Barnett</link:label>
    <link:label id="lab_smlp_BarnettShaleSegmentMember_label_en-US" xlink:label="lab_smlp_BarnettShaleSegmentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Barnett Shale Segment [Member]</link:label>
    <link:label id="lab_smlp_BarnettShaleSegmentMember_documentation_en-US" xlink:label="lab_smlp_BarnettShaleSegmentMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Barnett Shale segment.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_BarnettShaleSegmentMember" xlink:href="smlp-20240331.xsd#smlp_BarnettShaleSegmentMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_BarnettShaleSegmentMember" xlink:to="lab_smlp_BarnettShaleSegmentMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_1211b111-ea1c-48e3-8128-7a1537fbef27_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2028</link:label>
    <link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_label_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Debt, Maturity, Year Four</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:to="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_DebtInstrumentCovenantExceedsCashThresholdMember_412cd94d-bd90-4b3d-90df-16f186317cc0_terseLabel_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantExceedsCashThresholdMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Exceeds cash threshold</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantExceedsCashThresholdMember_label_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantExceedsCashThresholdMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Exceeds Cash Threshold [Member]</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantExceedsCashThresholdMember_documentation_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantExceedsCashThresholdMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Exceeds Cash Threshold</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_DebtInstrumentCovenantExceedsCashThresholdMember" xlink:href="smlp-20240331.xsd#smlp_DebtInstrumentCovenantExceedsCashThresholdMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_DebtInstrumentCovenantExceedsCashThresholdMember" xlink:to="lab_smlp_DebtInstrumentCovenantExceedsCashThresholdMember" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_DebtInstrumentRedemptionPriceOfferAmount_2a4f8cf3-dbec-4375-927b-067a479f28f8_terseLabel_en-US" xlink:label="lab_smlp_DebtInstrumentRedemptionPriceOfferAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt instrument, cash tender offer</link:label>
    <link:label id="lab_smlp_DebtInstrumentRedemptionPriceOfferAmount_label_en-US" xlink:label="lab_smlp_DebtInstrumentRedemptionPriceOfferAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Redemption Price, Offer Amount</link:label>
    <link:label id="lab_smlp_DebtInstrumentRedemptionPriceOfferAmount_documentation_en-US" xlink:label="lab_smlp_DebtInstrumentRedemptionPriceOfferAmount" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Debt Instrument, Redemption Price, Offer Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_DebtInstrumentRedemptionPriceOfferAmount" xlink:href="smlp-20240331.xsd#smlp_DebtInstrumentRedemptionPriceOfferAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_DebtInstrumentRedemptionPriceOfferAmount" xlink:to="lab_smlp_DebtInstrumentRedemptionPriceOfferAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_TwoThousandTwentyFiveSeniorNotesMember_5af97261-d595-4480-ba18-bff068da522e_terseLabel_en-US" xlink:label="lab_smlp_TwoThousandTwentyFiveSeniorNotesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2025 Senior Notes</link:label>
    <link:label id="lab_smlp_TwoThousandTwentyFiveSeniorNotesMember_label_en-US" xlink:label="lab_smlp_TwoThousandTwentyFiveSeniorNotesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Two Thousand Twenty Five Senior Notes [Member]</link:label>
    <link:label id="lab_smlp_TwoThousandTwentyFiveSeniorNotesMember_documentation_en-US" xlink:label="lab_smlp_TwoThousandTwentyFiveSeniorNotesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Two thousand twenty five senior notes.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_TwoThousandTwentyFiveSeniorNotesMember" xlink:href="smlp-20240331.xsd#smlp_TwoThousandTwentyFiveSeniorNotesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_TwoThousandTwentyFiveSeniorNotesMember" xlink:to="lab_smlp_TwoThousandTwentyFiveSeniorNotesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_A2026UnsecuredNotesMember_6590c0e5-46b3-4422-9b85-34079aaef6c9_terseLabel_en-US" xlink:label="lab_smlp_A2026UnsecuredNotesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2026 Unsecured Notes</link:label>
    <link:label id="lab_smlp_A2026UnsecuredNotesMember_label_en-US" xlink:label="lab_smlp_A2026UnsecuredNotesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">2026 Unsecured Notes [Member]</link:label>
    <link:label id="lab_smlp_A2026UnsecuredNotesMember_documentation_en-US" xlink:label="lab_smlp_A2026UnsecuredNotesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">2026 Unsecured Notes</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_A2026UnsecuredNotesMember" xlink:href="smlp-20240331.xsd#smlp_A2026UnsecuredNotesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_A2026UnsecuredNotesMember" xlink:to="lab_smlp_A2026UnsecuredNotesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CostsAndExpenses_8242f9c8-b3b9-4755-a341-94eacf0ae283_totalLabel_en-US" xlink:label="lab_us-gaap_CostsAndExpenses" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total costs and expenses</link:label>
    <link:label id="lab_us-gaap_CostsAndExpenses_label_en-US" xlink:label="lab_us-gaap_CostsAndExpenses" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Costs and Expenses</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpenses" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CostsAndExpenses"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CostsAndExpenses" xlink:to="lab_us-gaap_CostsAndExpenses" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_94d2587d-1786-453d-945c-fbfbd3836282_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other, net</link:label>
    <link:label id="lab_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_label_en-US" xlink:label="lab_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Proceeds from (Payments for) Other Financing Activities</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromPaymentsForOtherFinancingActivities"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:to="lab_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtInstrumentRepurchasedFaceAmount_e2ccff60-79ea-4ce8-baf0-d578400c14c9_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentRepurchasedFaceAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt instrument, repurchased face amount</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentRepurchasedFaceAmount_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentRepurchasedFaceAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Repurchased Face Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRepurchasedFaceAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentRepurchasedFaceAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentRepurchasedFaceAmount" xlink:to="lab_us-gaap_DebtInstrumentRepurchasedFaceAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_DocumentType_2e4de8d0-d3f1-4095-bd17-299fff98b937_terseLabel_en-US" xlink:label="lab_dei_DocumentType" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Document Type</link:label>
    <link:label id="lab_dei_DocumentType_label_en-US" xlink:label="lab_dei_DocumentType" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Type</link:label>
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    <link:label id="lab_dei_EntityAddressAddressLine1_caff6569-77f3-49d6-85fe-80bc3739dc80_terseLabel_en-US" xlink:label="lab_dei_EntityAddressAddressLine1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Entity Address, Address Line One</link:label>
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    <link:label id="lab_dei_EntityAddressAddressLine2_50385748-e1b6-43c9-ba43-58b7984a3eb4_terseLabel_en-US" xlink:label="lab_dei_EntityAddressAddressLine2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Entity Address, Address Line Two</link:label>
    <link:label id="lab_dei_EntityAddressAddressLine2_label_en-US" xlink:label="lab_dei_EntityAddressAddressLine2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Address, Address Line Two</link:label>
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    <link:label id="lab_smlp_SummitPermianTransmissionLLCMember_f0cd35e8-c791-422d-8636-c8f6259033b0_terseLabel_en-US" xlink:label="lab_smlp_SummitPermianTransmissionLLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Summit Permian Transmission, LLC</link:label>
    <link:label id="lab_smlp_SummitPermianTransmissionLLCMember_label_en-US" xlink:label="lab_smlp_SummitPermianTransmissionLLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Summit Permian Transmission, LLC [Member]</link:label>
    <link:label id="lab_smlp_SummitPermianTransmissionLLCMember_documentation_en-US" xlink:label="lab_smlp_SummitPermianTransmissionLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Summit Permian Transmission, LLC</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_SummitPermianTransmissionLLCMember" xlink:href="smlp-20240331.xsd#smlp_SummitPermianTransmissionLLCMember"/>
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    <link:label id="lab_us-gaap_SubsequentEventTable_4bf68828-1a02-44c2-9661-dc2942324178_terseLabel_en-US" xlink:label="lab_us-gaap_SubsequentEventTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Subsequent Event [Table]</link:label>
    <link:label id="lab_us-gaap_SubsequentEventTable_label_en-US" xlink:label="lab_us-gaap_SubsequentEventTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Subsequent Event [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsequentEventTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventTable" xlink:to="lab_us-gaap_SubsequentEventTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_87484d55-8b8c-44f1-ad40-92bc54d0d040_terseLabel_en-US" xlink:label="lab_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">UNIT-BASED AND NONCASH COMPENSATION</link:label>
    <link:label id="lab_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_label_en-US" xlink:label="lab_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Payment Arrangement [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:to="lab_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_BasisOfAccountingPolicyPolicyTextBlock_52bc10b3-c634-41f9-8cc1-b24a50fc9881_terseLabel_en-US" xlink:label="lab_us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Basis of Presentation</link:label>
    <link:label id="lab_us-gaap_BasisOfAccountingPolicyPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Basis of Accounting, Policy [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BasisOfAccountingPolicyPolicyTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:to="lab_us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal_17c015c4-13fd-4d0c-a9d9-1f9a001c328b_terseLabel_en-US" xlink:label="lab_us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Gain on sale of equity method investment</link:label>
    <link:label id="lab_us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal_e5c33d7f-99c7-4792-9942-2dd2926106ef_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Gain on sale of equity method investment</link:label>
    <link:label id="lab_us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal_label_en-US" xlink:label="lab_us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Equity Method Investment, Realized Gain (Loss) on Disposal</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal" xlink:to="lab_us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_BusinessAcquisitionAxis_453540e9-9234-4b3e-a8cb-9f0049436aab_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Business Acquisition</link:label>
    <link:label id="lab_us-gaap_BusinessAcquisitionAxis_label_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Business Acquisition [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessAcquisitionAxis" xlink:to="lab_us-gaap_BusinessAcquisitionAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_7d4e3514-5ae0-4e66-bad8-769469099ce2_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]</link:label>
    <link:label id="lab_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_label_en-US" xlink:label="lab_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems" xlink:to="lab_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DerivativeFairValueOfDerivativeNet_5186f822-7fd1-4505-b45e-a162f8bc519f_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeFairValueOfDerivativeNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair value of interest rate swap</link:label>
    <link:label id="lab_us-gaap_DerivativeFairValueOfDerivativeNet_label_en-US" xlink:label="lab_us-gaap_DerivativeFairValueOfDerivativeNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative, Fair Value, Net</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeNet" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeFairValueOfDerivativeNet"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeFairValueOfDerivativeNet" xlink:to="lab_us-gaap_DerivativeFairValueOfDerivativeNet" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccrualForEnvironmentalLossContingenciesPeriodIncreaseDecrease_5e0ca859-588e-4d2f-af6f-9bf189c433a8_terseLabel_en-US" xlink:label="lab_us-gaap_AccrualForEnvironmentalLossContingenciesPeriodIncreaseDecrease" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Changes in estimates</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccrualForEnvironmentalLossContingenciesPeriodIncreaseDecrease" xlink:to="lab_us-gaap_AccrualForEnvironmentalLossContingenciesPeriodIncreaseDecrease" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SubsequentEventMember_e9cf1e2b-42d1-4146-a4e9-b6ace6050cea_terseLabel_en-US" xlink:label="lab_us-gaap_SubsequentEventMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Subsequent Event</link:label>
    <link:label id="lab_us-gaap_SubsequentEventMember_label_en-US" xlink:label="lab_us-gaap_SubsequentEventMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Subsequent Event [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsequentEventMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventMember" xlink:to="lab_us-gaap_SubsequentEventMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherLiabilitiesCurrent_96d13247-186b-40c9-a36f-93bfc708e1ec_terseLabel_en-US" xlink:label="lab_us-gaap_OtherLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other current liabilities</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherLiabilitiesCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherLiabilitiesCurrent" xlink:to="lab_us-gaap_OtherLiabilitiesCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_AdjustmentsRelatedToCapitalReimbursementActivity_e93661ae-626d-4d90-9872-dd7fa74ee0fd_negatedLabel_en-US" xlink:label="lab_smlp_AdjustmentsRelatedToCapitalReimbursementActivity" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Adjustments related to capital reimbursement activity</link:label>
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    <link:label id="lab_smlp_AdjustmentsRelatedToCapitalReimbursementActivity_documentation_en-US" xlink:label="lab_smlp_AdjustmentsRelatedToCapitalReimbursementActivity" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Adjustments related to capital reimbursement activity.</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_AdjustmentsRelatedToCapitalReimbursementActivity" xlink:to="lab_smlp_AdjustmentsRelatedToCapitalReimbursementActivity" xlink:type="arc" order="1"/>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_PhantomShareUnitsAndAssociatedDistributionEquivalentRightsMember" xlink:to="lab_smlp_PhantomShareUnitsAndAssociatedDistributionEquivalentRightsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_VariableRateAxis_ec4498af-4a11-4449-9de3-69efbceac618_terseLabel_en-US" xlink:label="lab_us-gaap_VariableRateAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Variable Rate</link:label>
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    <link:label id="lab_us-gaap_IncomeStatementAbstract_d6d79343-8955-4cf8-92a3-45200c4695b1_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeStatementAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Income Statement [Abstract]</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeStatementAbstract" xlink:to="lab_us-gaap_IncomeStatementAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CostsAndExpensesAbstract_16ac8a06-24c4-4e66-9424-929dec117d2a_terseLabel_en-US" xlink:label="lab_us-gaap_CostsAndExpensesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Costs and expenses:</link:label>
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    <link:label id="lab_smlp_A2026NotesMember_label_en-US" xlink:label="lab_smlp_A2026NotesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">2026 Notes [Member]</link:label>
    <link:label id="lab_smlp_A2026NotesMember_documentation_en-US" xlink:label="lab_smlp_A2026NotesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">2026 Notes</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_A2026NotesMember" xlink:href="smlp-20240331.xsd#smlp_A2026NotesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_A2026NotesMember" xlink:to="lab_smlp_A2026NotesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_Security12bTitle_cb825d89-0ce4-4a78-ae11-bef517ae2a48_terseLabel_en-US" xlink:label="lab_dei_Security12bTitle" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Title of 12(b) Security</link:label>
    <link:label id="lab_dei_Security12bTitle_label_en-US" xlink:label="lab_dei_Security12bTitle" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Title of 12(b) Security</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_Security12bTitle"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_Security12bTitle" xlink:to="lab_dei_Security12bTitle" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodTwo_eaded738-4074-4edc-8f6a-e19b09c4124f_terseLabel_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodTwo" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt instrument, covenant, excess cash flow offer to purchase, period two</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodTwo_label_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodTwo" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Excess Cash Flow Offer To Purchase, Period Two</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodTwo_documentation_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodTwo" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Excess Cash Flow Offer To Purchase, Period Two</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodTwo" xlink:href="smlp-20240331.xsd#smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodTwo"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodTwo" xlink:to="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchasePeriodTwo" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccrualForEnvironmentalLossContingenciesDiscountRate_799f294a-623e-4ad4-b8c7-e316b125e8ff_terseLabel_en-US" xlink:label="lab_us-gaap_AccrualForEnvironmentalLossContingenciesDiscountRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Unpaid penalties and fines, fixed rate (as a percent)</link:label>
    <link:label id="lab_us-gaap_AccrualForEnvironmentalLossContingenciesDiscountRate_label_en-US" xlink:label="lab_us-gaap_AccrualForEnvironmentalLossContingenciesDiscountRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accrual for Environmental Loss Contingencies, Discount Rate</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccrualForEnvironmentalLossContingenciesDiscountRate" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccrualForEnvironmentalLossContingenciesDiscountRate"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccrualForEnvironmentalLossContingenciesDiscountRate" xlink:to="lab_us-gaap_AccrualForEnvironmentalLossContingenciesDiscountRate" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LossContingencyNatureDomain_d8a233ff-ac58-49aa-ab84-0a220f04301e_terseLabel_en-US" xlink:label="lab_us-gaap_LossContingencyNatureDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Loss Contingency, Nature [Domain]</link:label>
    <link:label id="lab_us-gaap_LossContingencyNatureDomain_label_en-US" xlink:label="lab_us-gaap_LossContingencyNatureDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Loss Contingency, Nature [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LossContingencyNatureDomain" xlink:to="lab_us-gaap_LossContingencyNatureDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OperatingSegmentsMember_ee2181de-7b59-43bd-864f-8c171cffaed1_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingSegmentsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Reportable Segments</link:label>
    <link:label id="lab_us-gaap_OperatingSegmentsMember_label_en-US" xlink:label="lab_us-gaap_OperatingSegmentsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Segments [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingSegmentsMember" xlink:to="lab_us-gaap_OperatingSegmentsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherAssetsCurrent_1aec0b40-e80c-463f-8560-1d29079fd5c1_terseLabel_en-US" xlink:label="lab_us-gaap_OtherAssetsCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other current assets</link:label>
    <link:label id="lab_us-gaap_OtherAssetsCurrent_label_en-US" xlink:label="lab_us-gaap_OtherAssetsCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Assets, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherAssetsCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherAssetsCurrent" xlink:to="lab_us-gaap_OtherAssetsCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ClassOfStockLineItems_e3b9da10-d53d-441f-ab30-374c82b4653d_terseLabel_en-US" xlink:label="lab_us-gaap_ClassOfStockLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Class of Stock [Line Items]</link:label>
    <link:label id="lab_us-gaap_ClassOfStockLineItems_label_en-US" xlink:label="lab_us-gaap_ClassOfStockLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Class of Stock [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ClassOfStockLineItems" xlink:to="lab_us-gaap_ClassOfStockLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_2cde3c68-8e6f-4913-bd3e-fefd71efdf1d_terseLabel_en-US" xlink:label="lab_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Payment Arrangement [Abstract]</link:label>
    <link:label id="lab_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_label_en-US" xlink:label="lab_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Payment Arrangement [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="lab_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_EntityTaxIdentificationNumber_32ae15d1-c740-4d32-ba04-f19dfeef8544_terseLabel_en-US" xlink:label="lab_dei_EntityTaxIdentificationNumber" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Entity Tax Identification Number</link:label>
    <link:label id="lab_dei_EntityTaxIdentificationNumber_label_en-US" xlink:label="lab_dei_EntityTaxIdentificationNumber" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Tax Identification Number</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityTaxIdentificationNumber" xlink:to="lab_dei_EntityTaxIdentificationNumber" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EquityMethodInvestments_1835c101-29c6-4c26-b767-acd748430170_terseLabel_en-US" xlink:label="lab_us-gaap_EquityMethodInvestments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Investment in equity method investees</link:label>
    <link:label id="lab_us-gaap_EquityMethodInvestments_label_en-US" xlink:label="lab_us-gaap_EquityMethodInvestments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Equity Method Investments</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestments" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityMethodInvestments"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EquityMethodInvestments" xlink:to="lab_us-gaap_EquityMethodInvestments" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock_a507920e-0f31-4134-af39-4c8d535ed508_verboseLabel_en-US" xlink:label="lab_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">DIVESTITURES</link:label>
    <link:label id="lab_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock" xlink:to="lab_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_EntityInteractiveDataCurrent_19d9f20f-ddb7-49dd-b836-1a782baaee71_terseLabel_en-US" xlink:label="lab_dei_EntityInteractiveDataCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Entity Interactive Data Current</link:label>
    <link:label id="lab_dei_EntityInteractiveDataCurrent_label_en-US" xlink:label="lab_dei_EntityInteractiveDataCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Interactive Data Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInteractiveDataCurrent" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityInteractiveDataCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityInteractiveDataCurrent" xlink:to="lab_dei_EntityInteractiveDataCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_A2015BlacktailReleaseMember_52c6678c-4002-43cd-9946-e959d2ba6f96_terseLabel_en-US" xlink:label="lab_smlp_A2015BlacktailReleaseMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2015 Blacktail Release</link:label>
    <link:label id="lab_smlp_A2015BlacktailReleaseMember_label_en-US" xlink:label="lab_smlp_A2015BlacktailReleaseMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">2015 Blacktail Release [Member]</link:label>
    <link:label id="lab_smlp_A2015BlacktailReleaseMember_documentation_en-US" xlink:label="lab_smlp_A2015BlacktailReleaseMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">2015 Blacktail Release</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_A2015BlacktailReleaseMember" xlink:href="smlp-20240331.xsd#smlp_A2015BlacktailReleaseMember"/>
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    <link:label id="lab_us-gaap_DisaggregationOfRevenueTable_ca7c3128-1b51-4ea1-8adc-18becefe87bc_terseLabel_en-US" xlink:label="lab_us-gaap_DisaggregationOfRevenueTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Disaggregation of Revenue [Table]</link:label>
    <link:label id="lab_us-gaap_DisaggregationOfRevenueTable_label_en-US" xlink:label="lab_us-gaap_DisaggregationOfRevenueTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disaggregation of Revenue [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable" xlink:to="lab_us-gaap_DisaggregationOfRevenueTable" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_PartnersCapitalMember_bcffa70c-d551-462e-b68e-31a4d5e65606_terseLabel_en-US" xlink:label="lab_smlp_PartnersCapitalMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Common Limited Partners Capital</link:label>
    <link:label id="lab_smlp_PartnersCapitalMember_label_en-US" xlink:label="lab_smlp_PartnersCapitalMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Partners Capital [Member]</link:label>
    <link:label id="lab_smlp_PartnersCapitalMember_documentation_en-US" xlink:label="lab_smlp_PartnersCapitalMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Partners capital.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_PartnersCapitalMember" xlink:href="smlp-20240331.xsd#smlp_PartnersCapitalMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_PartnersCapitalMember" xlink:to="lab_smlp_PartnersCapitalMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EarningsPerLimitedPartnershipUnitAbstract_6683370b-642c-4e73-980d-f894e3a10eab_terseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerLimitedPartnershipUnitAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Net income (loss) per limited partner unit:</link:label>
    <link:label id="lab_us-gaap_EarningsPerLimitedPartnershipUnitAbstract_label_en-US" xlink:label="lab_us-gaap_EarningsPerLimitedPartnershipUnitAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net Income (Loss), Per Outstanding Limited Partnership Unit, Basic, Net of Tax [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerLimitedPartnershipUnitAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EarningsPerLimitedPartnershipUnitAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EarningsPerLimitedPartnershipUnitAbstract" xlink:to="lab_us-gaap_EarningsPerLimitedPartnershipUnitAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_DebtInstrumentCovenantRepurchaseAmountOfPrincipalPlusAccruedInterest_e4cdb396-510b-4906-81f8-9b062d33e54e_terseLabel_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantRepurchaseAmountOfPrincipalPlusAccruedInterest" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt instrument, principal interest rate</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantRepurchaseAmountOfPrincipalPlusAccruedInterest_label_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantRepurchaseAmountOfPrincipalPlusAccruedInterest" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Repurchase Amount Of Principal Plus Accrued Interest</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantRepurchaseAmountOfPrincipalPlusAccruedInterest_documentation_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantRepurchaseAmountOfPrincipalPlusAccruedInterest" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Repurchase Amount Of Principal Plus Accrued Interest</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_DebtInstrumentCovenantRepurchaseAmountOfPrincipalPlusAccruedInterest" xlink:href="smlp-20240331.xsd#smlp_DebtInstrumentCovenantRepurchaseAmountOfPrincipalPlusAccruedInterest"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_DebtInstrumentCovenantRepurchaseAmountOfPrincipalPlusAccruedInterest" xlink:to="lab_smlp_DebtInstrumentCovenantRepurchaseAmountOfPrincipalPlusAccruedInterest" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_EntityCommonStockSharesOutstanding_57240cf0-c8c9-466c-85a9-1c9b0874c169_terseLabel_en-US" xlink:label="lab_dei_EntityCommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Entity Common Stock, Shares Outstanding</link:label>
    <link:label id="lab_dei_EntityCommonStockSharesOutstanding_label_en-US" xlink:label="lab_dei_EntityCommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Common Stock, Shares Outstanding</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCommonStockSharesOutstanding"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityCommonStockSharesOutstanding" xlink:to="lab_dei_EntityCommonStockSharesOutstanding" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SegmentDomain_51b2e456-a292-41ae-9021-a72a3808cecd_terseLabel_en-US" xlink:label="lab_us-gaap_SegmentDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Segments</link:label>
    <link:label id="lab_us-gaap_SegmentDomain_label_en-US" xlink:label="lab_us-gaap_SegmentDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Segments [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SegmentDomain" xlink:to="lab_us-gaap_SegmentDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_98d5c89c-4bf1-49ff-a41a-1c34d1c437fd_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award [Line Items]</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis_2ec70744-a22e-4606-8999-9ff6c50145d9_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value Hierarchy and NAV</link:label>
    <link:label id="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis_label_en-US" xlink:label="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value Hierarchy and NAV [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncreaseDecreaseInPropertyAndOtherTaxesPayable_922d3ad4-d3f8-4ab5-9e50-4e692f82328d_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInPropertyAndOtherTaxesPayable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Ad valorem taxes payable</link:label>
    <link:label id="lab_us-gaap_IncreaseDecreaseInPropertyAndOtherTaxesPayable_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInPropertyAndOtherTaxesPayable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Increase (Decrease) in Property and Other Taxes Payable</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPropertyAndOtherTaxesPayable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInPropertyAndOtherTaxesPayable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInPropertyAndOtherTaxesPayable" xlink:to="lab_us-gaap_IncreaseDecreaseInPropertyAndOtherTaxesPayable" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_DoubleECompanyLLCMember_67f5de41-9453-4475-9c89-268aae63d552_terseLabel_en-US" xlink:label="lab_smlp_DoubleECompanyLLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Double E</link:label>
    <link:label id="lab_smlp_DoubleECompanyLLCMember_label_en-US" xlink:label="lab_smlp_DoubleECompanyLLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Double E Company L L C [Member]</link:label>
    <link:label id="lab_smlp_DoubleECompanyLLCMember_documentation_en-US" xlink:label="lab_smlp_DoubleECompanyLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Double E company.</link:label>
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    <link:label id="lab_srt_ConsolidationItemsDomain_7e602911-1497-491d-927a-44a38e742ea9_terseLabel_en-US" xlink:label="lab_srt_ConsolidationItemsDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Consolidation Items</link:label>
    <link:label id="lab_srt_ConsolidationItemsDomain_label_en-US" xlink:label="lab_srt_ConsolidationItemsDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Consolidation Items [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidationItemsDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_ConsolidationItemsDomain" xlink:to="lab_srt_ConsolidationItemsDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PaymentsOfCapitalDistribution_f8b1d1a8-68c1-41e4-b95c-8d416796431d_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_PaymentsOfCapitalDistribution" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Distributions on Subsidiary Series A Preferred Units</link:label>
    <link:label id="lab_us-gaap_PaymentsOfCapitalDistribution_label_en-US" xlink:label="lab_us-gaap_PaymentsOfCapitalDistribution" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Payments of Capital Distribution</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfCapitalDistribution" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsOfCapitalDistribution"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsOfCapitalDistribution" xlink:to="lab_us-gaap_PaymentsOfCapitalDistribution" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CommitmentsAndContingenciesDisclosureAbstract_59053326-d59c-4e35-94cb-9f04b772dd87_terseLabel_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Commitments and Contingencies Disclosure [Abstract]</link:label>
    <link:label id="lab_us-gaap_CommitmentsAndContingenciesDisclosureAbstract_label_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Commitments and Contingencies Disclosure [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:to="lab_us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_DistributionOfAllAvailableCashMaximumPeriodFollowingEndOfQuarter_b9a16796-accc-4f4d-af08-269688e52e14_terseLabel_en-US" xlink:label="lab_smlp_DistributionOfAllAvailableCashMaximumPeriodFollowingEndOfQuarter" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Maximum period following end of quarter to distribute all available cash</link:label>
    <link:label id="lab_smlp_DistributionOfAllAvailableCashMaximumPeriodFollowingEndOfQuarter_label_en-US" xlink:label="lab_smlp_DistributionOfAllAvailableCashMaximumPeriodFollowingEndOfQuarter" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Distribution Of All Available Cash Maximum Period Following End Of Quarter</link:label>
    <link:label id="lab_smlp_DistributionOfAllAvailableCashMaximumPeriodFollowingEndOfQuarter_documentation_en-US" xlink:label="lab_smlp_DistributionOfAllAvailableCashMaximumPeriodFollowingEndOfQuarter" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Distribution of all available cash, maximum period following end of quarter.</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_DistributionOfAllAvailableCashMaximumPeriodFollowingEndOfQuarter" xlink:to="lab_smlp_DistributionOfAllAvailableCashMaximumPeriodFollowingEndOfQuarter" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtInstrumentFaceAmount_e7655502-e07e-4098-954d-a6ce34ad0006_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentFaceAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt offering</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentFaceAmount_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentFaceAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Face Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentFaceAmount" xlink:to="lab_us-gaap_DebtInstrumentFaceAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_EntityIncorporationStateCountryCode_cc420998-9984-4036-a27e-7e2e4f375399_terseLabel_en-US" xlink:label="lab_dei_EntityIncorporationStateCountryCode" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Entity Incorporation, State or Country Code</link:label>
    <link:label id="lab_dei_EntityIncorporationStateCountryCode_label_en-US" xlink:label="lab_dei_EntityIncorporationStateCountryCode" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Incorporation, State or Country Code</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityIncorporationStateCountryCode" xlink:to="lab_dei_EntityIncorporationStateCountryCode" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetTextBlock_8c956ddf-2701-49cf-839d-38aa42ca3542_terseLabel_en-US" xlink:label="lab_us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net</link:label>
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    <link:label id="lab_dei_EntityAddressStateOrProvince_dceaabd1-8057-495a-bc16-82b6d54006e7_terseLabel_en-US" xlink:label="lab_dei_EntityAddressStateOrProvince" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Entity Address, State or Province</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityAddressStateOrProvince" xlink:to="lab_dei_EntityAddressStateOrProvince" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_CounterpartyNameAxis_e367bc61-5cbd-4711-a23d-af6bb9bb8d43_terseLabel_en-US" xlink:label="lab_srt_CounterpartyNameAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Counterparty Name [Axis]</link:label>
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    <link:label id="lab_us-gaap_ScheduleOfCarryingValuesAndEstimatedFairValuesOfDebtInstrumentsTableTextBlock_e10de1bf-29f5-4079-add1-6f0336612120_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfCarryingValuesAndEstimatedFairValuesOfDebtInstrumentsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Carrying Values and Estimated Fair Values of Debt Instruments</link:label>
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    <link:label id="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_875994d7-1188-4716-b00b-3bb2d15b0d5e_terseLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Cash flows from operating activities:</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_ScheduleOfDepreciationExpenseAndCapitalizedInterestCostTableTextBlock_811e527e-e2e3-43bc-a79c-15db346fd65a_terseLabel_en-US" xlink:label="lab_smlp_ScheduleOfDepreciationExpenseAndCapitalizedInterestCostTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule Of Depreciation Expense And Capitalized Interest Costs</link:label>
    <link:label id="lab_smlp_ScheduleOfDepreciationExpenseAndCapitalizedInterestCostTableTextBlock_label_en-US" xlink:label="lab_smlp_ScheduleOfDepreciationExpenseAndCapitalizedInterestCostTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule Of Depreciation Expense And Capitalized Interest Cost [Table Text Block]</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_ScheduleOfDepreciationExpenseAndCapitalizedInterestCostTableTextBlock" xlink:to="lab_smlp_ScheduleOfDepreciationExpenseAndCapitalizedInterestCostTableTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncreaseDecreaseInInterestPayableNet_f70ecd4c-f606-4d46-aa1c-a1ad50b45f2e_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInInterestPayableNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accrued interest</link:label>
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    <link:label id="lab_smlp_OtherCreditFacilityReservesMember_48509274-7e2b-48f5-aef8-52c8fb8a86eb_terseLabel_en-US" xlink:label="lab_smlp_OtherCreditFacilityReservesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other Credit Facility Reserves</link:label>
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    <link:label id="lab_us-gaap_ClassOfStockDomain_cffbaaa5-46eb-468a-95ba-c32eb46307a8_verboseLabel_en-US" xlink:label="lab_us-gaap_ClassOfStockDomain" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Class of Stock</link:label>
    <link:label id="lab_us-gaap_ClassOfStockDomain_label_en-US" xlink:label="lab_us-gaap_ClassOfStockDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Class of Stock [Domain]</link:label>
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    <link:label id="lab_us-gaap_CreditFacilityAxis_b93d944f-f580-4943-9f84-baf9c203d407_terseLabel_en-US" xlink:label="lab_us-gaap_CreditFacilityAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Credit Facility</link:label>
    <link:label id="lab_us-gaap_CreditFacilityAxis_label_en-US" xlink:label="lab_us-gaap_CreditFacilityAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Credit Facility [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityAxis"/>
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    <link:label id="lab_us-gaap_Liabilities_a7e7d669-a7f7-4739-84f4-3f478e81f43e_totalLabel_en-US" xlink:label="lab_us-gaap_Liabilities" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">TOTAL LIABILITIES</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Liabilities"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_Liabilities" xlink:to="lab_us-gaap_Liabilities" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock_451375ed-ca02-47b4-9810-82fa68913ef9_terseLabel_en-US" xlink:label="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">ORGANIZATION, BUSINESS OPERATIONS AND PRESENTATION AND CONSOLIDATION</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock"/>
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    <link:label id="lab_us-gaap_EnvironmentalRemediationSiteAxis_label_en-US" xlink:label="lab_us-gaap_EnvironmentalRemediationSiteAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Environmental Remediation Site [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EnvironmentalRemediationSiteAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EnvironmentalRemediationSiteAxis"/>
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    <link:label id="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration_c03b94dd-3abc-45b8-af45-1a20829e782d_terseLabel_en-US" xlink:label="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Cash consideration</link:label>
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    <link:label id="lab_smlp_SeniorUnsecuredNotesDueTwentyTwentySixMember_79db3b05-f327-47d6-a5e6-dbed1f677fec_terseLabel_en-US" xlink:label="lab_smlp_SeniorUnsecuredNotesDueTwentyTwentySixMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2026 Unsecured Notes</link:label>
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    <link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_20463031-7ebc-4e44-ac1b-63b529afde09_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]</link:label>
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    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_c67efd67-069a-4440-b27c-f3c591a91da8_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">PROPERTY, PLANT AND EQUIPMENT</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:to="lab_us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RevenueFromContractWithCustomerAbstract_4eca6d42-a6f2-468e-b45e-8ca5c13e6184_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueFromContractWithCustomerAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Revenue from Contract with Customer [Abstract]</link:label>
    <link:label id="lab_us-gaap_RevenueFromContractWithCustomerAbstract_label_en-US" xlink:label="lab_us-gaap_RevenueFromContractWithCustomerAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenue from Contract with Customer [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromContractWithCustomerAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenueFromContractWithCustomerAbstract" xlink:to="lab_us-gaap_RevenueFromContractWithCustomerAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RestrictedCash_82310a74-15bc-4036-9e24-d99f4256181d_terseLabel_en-US" xlink:label="lab_us-gaap_RestrictedCash" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Restricted cash</link:label>
    <link:label id="lab_us-gaap_RestrictedCash_label_en-US" xlink:label="lab_us-gaap_RestrictedCash" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Restricted Cash</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCash" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestrictedCash"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RestrictedCash" xlink:to="lab_us-gaap_RestrictedCash" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SupplementalCashFlowInformationAbstract_3591faa9-f873-41dc-b799-00d3b097e83c_terseLabel_en-US" xlink:label="lab_us-gaap_SupplementalCashFlowInformationAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Supplemental cash flow information:</link:label>
    <link:label id="lab_us-gaap_SupplementalCashFlowInformationAbstract_label_en-US" xlink:label="lab_us-gaap_SupplementalCashFlowInformationAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Supplemental Cash Flow Information [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplementalCashFlowInformationAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SupplementalCashFlowInformationAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract" xlink:to="lab_us-gaap_SupplementalCashFlowInformationAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_SeniorNotesDueAprilTwentyTwentyFiveMember_2df85fd4-761a-406f-a7ed-279bdd55fcca_terseLabel_en-US" xlink:label="lab_smlp_SeniorNotesDueAprilTwentyTwentyFiveMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2025 Senior Notes: 5.75% senior unsecured notes due April 15, 2025</link:label>
    <link:label id="lab_smlp_SeniorNotesDueAprilTwentyTwentyFiveMember_label_en-US" xlink:label="lab_smlp_SeniorNotesDueAprilTwentyTwentyFiveMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Senior Notes Due April Twenty Twenty Five [Member]</link:label>
    <link:label id="lab_smlp_SeniorNotesDueAprilTwentyTwentyFiveMember_documentation_en-US" xlink:label="lab_smlp_SeniorNotesDueAprilTwentyTwentyFiveMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Senior notes due April twenty twenty five.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_SeniorNotesDueAprilTwentyTwentyFiveMember" xlink:href="smlp-20240331.xsd#smlp_SeniorNotesDueAprilTwentyTwentyFiveMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_SeniorNotesDueAprilTwentyTwentyFiveMember" xlink:to="lab_smlp_SeniorNotesDueAprilTwentyTwentyFiveMember" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_LitigationCaseTypeDomain_e814a860-95fa-49ed-a8c0-1b7d1d16f053_terseLabel_en-US" xlink:label="lab_srt_LitigationCaseTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Litigation Case [Domain]</link:label>
    <link:label id="lab_srt_LitigationCaseTypeDomain_label_en-US" xlink:label="lab_srt_LitigationCaseTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Litigation Case [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_LitigationCaseTypeDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_LitigationCaseTypeDomain" xlink:to="lab_srt_LitigationCaseTypeDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_EntityFilerCategory_f7ca7cff-c1f0-492a-8142-e178c85010ae_terseLabel_en-US" xlink:label="lab_dei_EntityFilerCategory" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Entity Filer Category</link:label>
    <link:label id="lab_dei_EntityFilerCategory_label_en-US" xlink:label="lab_dei_EntityFilerCategory" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Filer Category</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityFilerCategory"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityFilerCategory" xlink:to="lab_dei_EntityFilerCategory" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_fb26a122-2622-4757-b768-c3d57f4bb78a_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Equity Method Investments [Line Items]</link:label>
    <link:label id="lab_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_label_en-US" xlink:label="lab_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Equity Method Investments [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems" xlink:to="lab_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PartnersCapital_42f41b54-e3b1-42f7-8b0f-5d54ee6604e0_periodStartLabel_en-US" xlink:label="lab_us-gaap_PartnersCapital" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Beginning balance</link:label>
    <link:label id="lab_us-gaap_PartnersCapital_917f546a-d234-4651-ae23-719daf799a8d_periodEndLabel_en-US" xlink:label="lab_us-gaap_PartnersCapital" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Ending balance</link:label>
    <link:label id="lab_us-gaap_PartnersCapital_label_en-US" xlink:label="lab_us-gaap_PartnersCapital" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Partners' Capital</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PartnersCapital" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PartnersCapital"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PartnersCapital" xlink:to="lab_us-gaap_PartnersCapital" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StatementTable_fc183733-353d-460b-9815-d5930c5a3333_terseLabel_en-US" xlink:label="lab_us-gaap_StatementTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Statement [Table]</link:label>
    <link:label id="lab_us-gaap_StatementTable_label_en-US" xlink:label="lab_us-gaap_StatementTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statement [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementTable" xlink:to="lab_us-gaap_StatementTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_3bd31a2f-6a06-47fc-a346-d96b58b31e1c_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Increase (Decrease) in Partners' Capital [Roll Forward]</link:label>
    <link:label id="lab_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Increase (Decrease) in Partners' Capital [Roll Forward]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInPartnersCapitalRollForward"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward" xlink:to="lab_us-gaap_IncreaseDecreaseInPartnersCapitalRollForward" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_CurrentFiscalYearEndDate_7230c5ce-924e-48bf-a9fe-e6882b874123_terseLabel_en-US" xlink:label="lab_dei_CurrentFiscalYearEndDate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Current Fiscal Year End Date</link:label>
    <link:label id="lab_dei_CurrentFiscalYearEndDate_label_en-US" xlink:label="lab_dei_CurrentFiscalYearEndDate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Current Fiscal Year End Date</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_CurrentFiscalYearEndDate"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_CurrentFiscalYearEndDate" xlink:to="lab_dei_CurrentFiscalYearEndDate" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_SterlingDJMember_0919d80d-8677-49f4-8df2-1cee99842eb6_terseLabel_en-US" xlink:label="lab_smlp_SterlingDJMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Sterling DJ</link:label>
    <link:label id="lab_smlp_SterlingDJMember_label_en-US" xlink:label="lab_smlp_SterlingDJMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sterling DJ [Member]</link:label>
    <link:label id="lab_smlp_SterlingDJMember_documentation_en-US" xlink:label="lab_smlp_SterlingDJMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Sterling DJ</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_SterlingDJMember" xlink:href="smlp-20240331.xsd#smlp_SterlingDJMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_SterlingDJMember" xlink:to="lab_smlp_SterlingDJMember" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_PartnersCapitalTable_b721f9e4-6fa1-4554-abc3-5585cd18e5e9_terseLabel_en-US" xlink:label="lab_smlp_PartnersCapitalTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Partners Capital [Table]</link:label>
    <link:label id="lab_smlp_PartnersCapitalTable_label_en-US" xlink:label="lab_smlp_PartnersCapitalTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Partners Capital [Table]</link:label>
    <link:label id="lab_smlp_PartnersCapitalTable_documentation_en-US" xlink:label="lab_smlp_PartnersCapitalTable" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Partners' capital.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_PartnersCapitalTable" xlink:href="smlp-20240331.xsd#smlp_PartnersCapitalTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_PartnersCapitalTable" xlink:to="lab_smlp_PartnersCapitalTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueByBalanceSheetGroupingTable_cb9f0d5a-d3d1-4903-8cfc-6f441c157b6b_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueByBalanceSheetGroupingTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value, by Balance Sheet Grouping [Table]</link:label>
    <link:label id="lab_us-gaap_FairValueByBalanceSheetGroupingTable_label_en-US" xlink:label="lab_us-gaap_FairValueByBalanceSheetGroupingTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, by Balance Sheet Grouping [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByBalanceSheetGroupingTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable" xlink:to="lab_us-gaap_FairValueByBalanceSheetGroupingTable" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_MountaineerMidstreamCompanyLLCMember_a9061b46-5d4b-4f80-a6d8-cb3de92a27cb_terseLabel_en-US" xlink:label="lab_smlp_MountaineerMidstreamCompanyLLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Mountaineer Midstream Company, LLC</link:label>
    <link:label id="lab_smlp_MountaineerMidstreamCompanyLLCMember_label_en-US" xlink:label="lab_smlp_MountaineerMidstreamCompanyLLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Mountaineer Midstream Company, LLC [Member]</link:label>
    <link:label id="lab_smlp_MountaineerMidstreamCompanyLLCMember_documentation_en-US" xlink:label="lab_smlp_MountaineerMidstreamCompanyLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Mountaineer Midstream Company, LLC</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_MountaineerMidstreamCompanyLLCMember" xlink:href="smlp-20240331.xsd#smlp_MountaineerMidstreamCompanyLLCMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_MountaineerMidstreamCompanyLLCMember" xlink:to="lab_smlp_MountaineerMidstreamCompanyLLCMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PreferredUnitsIssued_5f596b92-1330-47e5-a7fb-483f6711d68a_verboseLabel_en-US" xlink:label="lab_us-gaap_PreferredUnitsIssued" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Subsidiary Series A preferred unitholders, issued (in shares)</link:label>
    <link:label id="lab_us-gaap_PreferredUnitsIssued_0cbcb518-0368-4fd5-9852-d9b8db4a7787_terseLabel_en-US" xlink:label="lab_us-gaap_PreferredUnitsIssued" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Preferred units issued (in shares)</link:label>
    <link:label id="lab_us-gaap_PreferredUnitsIssued_label_en-US" xlink:label="lab_us-gaap_PreferredUnitsIssued" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Preferred Units, Issued</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredUnitsIssued" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredUnitsIssued"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredUnitsIssued" xlink:to="lab_us-gaap_PreferredUnitsIssued" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities_c3ef3fa0-e014-4421-b85c-a8e82b1e652e_totalLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net cash provided by operating activities</link:label>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net Cash Provided by (Used in) Operating Activities</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StatementClassOfStockAxis_5ee1ae31-d1d8-4d92-a457-5de7add225f9_verboseLabel_en-US" xlink:label="lab_us-gaap_StatementClassOfStockAxis" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Class of Stock</link:label>
    <link:label id="lab_us-gaap_StatementClassOfStockAxis_3040a34a-3f16-4b7b-b0be-9b3d9d953078_terseLabel_en-US" xlink:label="lab_us-gaap_StatementClassOfStockAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Class of Stock</link:label>
    <link:label id="lab_us-gaap_StatementClassOfStockAxis_label_en-US" xlink:label="lab_us-gaap_StatementClassOfStockAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Class of Stock [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementClassOfStockAxis" xlink:to="lab_us-gaap_StatementClassOfStockAxis" xlink:type="arc" order="1"/>
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    <link:label id="lab_smlp_OCCMember_label_en-US" xlink:label="lab_smlp_OCCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">OCC [Member]</link:label>
    <link:label id="lab_smlp_OCCMember_documentation_en-US" xlink:label="lab_smlp_OCCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">OCC</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_OCCMember" xlink:href="smlp-20240331.xsd#smlp_OCCMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_OCCMember" xlink:to="lab_smlp_OCCMember" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_DebtInstrumentCovenantThresholdDomain_3d447b06-2d10-4b8b-ae5b-dd2aa6dad70c_terseLabel_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantThresholdDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Threshold [Domain]</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantThresholdDomain_label_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantThresholdDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Threshold [Domain]</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantThresholdDomain_documentation_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantThresholdDomain" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Threshold [Domain]</link:label>
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    <link:label id="lab_us-gaap_CorporateNonSegmentMember_768af3e4-0f61-4b1f-a4c5-6219de08b37c_terseLabel_en-US" xlink:label="lab_us-gaap_CorporateNonSegmentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Corporate and Other</link:label>
    <link:label id="lab_us-gaap_CorporateNonSegmentMember_label_en-US" xlink:label="lab_us-gaap_CorporateNonSegmentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Corporate, Non-Segment [Member]</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CorporateNonSegmentMember" xlink:to="lab_us-gaap_CorporateNonSegmentMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtInstrumentRedemptionPeriodThreeMember_2d7211ec-3cbb-41ce-a563-06fdac83b09d_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentRedemptionPeriodThreeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Beginning October 15, 2025</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodThreeMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentRedemptionPeriodThreeMember"/>
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    <link:label id="lab_us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet_87ee2b65-7670-494e-9252-af61e99171ba_negatedLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Other, net</link:label>
    <link:label id="lab_us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Increase (Decrease) in Other Operating Assets and Liabilities, Net</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet"/>
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    <link:label id="lab_us-gaap_DepreciationDepletionAndAmortization_label_en-US" xlink:label="lab_us-gaap_DepreciationDepletionAndAmortization" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Depreciation, Depletion and Amortization</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DepreciationDepletionAndAmortization" xlink:to="lab_us-gaap_DepreciationDepletionAndAmortization" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_AdjustedEarningsBeforeInterestTaxesDepreciationAndAmortization_6ec70abe-fc1c-4955-8973-8c57e95aef00_terseLabel_en-US" xlink:label="lab_smlp_AdjustedEarningsBeforeInterestTaxesDepreciationAndAmortization" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Adjusted EBITDA</link:label>
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    <link:label id="lab_smlp_AdjustedEarningsBeforeInterestTaxesDepreciationAndAmortization_documentation_en-US" xlink:label="lab_smlp_AdjustedEarningsBeforeInterestTaxesDepreciationAndAmortization" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Adjusted earnings before interest, taxes, depreciation, and amortization.</link:label>
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    <link:label id="lab_us-gaap_OtherOperatingIncomeExpenseNet_2d2dd70d-9814-432e-bf5e-e5c6c703a136_terseLabel_en-US" xlink:label="lab_us-gaap_OtherOperatingIncomeExpenseNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other income (expense), net</link:label>
    <link:label id="lab_us-gaap_OtherOperatingIncomeExpenseNet_label_en-US" xlink:label="lab_us-gaap_OtherOperatingIncomeExpenseNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Operating Income (Expense), Net</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherOperatingIncomeExpenseNet" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherOperatingIncomeExpenseNet"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherOperatingIncomeExpenseNet" xlink:to="lab_us-gaap_OtherOperatingIncomeExpenseNet" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtInstrumentInterestRateStatedPercentage_884314bf-cd33-4611-bd51-a2f366124432_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Stated interest rate (as a percent)</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
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    <link:label id="lab_us-gaap_StatementOfFinancialPositionAbstract_86a196f3-d52f-42d0-baee-d4b4fdcaf083_terseLabel_en-US" xlink:label="lab_us-gaap_StatementOfFinancialPositionAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Statement of Financial Position [Abstract]</link:label>
    <link:label id="lab_us-gaap_StatementOfFinancialPositionAbstract_label_en-US" xlink:label="lab_us-gaap_StatementOfFinancialPositionAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statement of Financial Position [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfFinancialPositionAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementOfFinancialPositionAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementOfFinancialPositionAbstract" xlink:to="lab_us-gaap_StatementOfFinancialPositionAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_GainLossOnSaleOfBusiness_443ccb24-b587-449b-ad5a-967fdaaea365_terseLabel_en-US" xlink:label="lab_us-gaap_GainLossOnSaleOfBusiness" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Gain on sale of business</link:label>
    <link:label id="lab_us-gaap_GainLossOnSaleOfBusiness_96282f91-1f17-48ac-b6b1-66769c0d0643_verboseLabel_en-US" xlink:label="lab_us-gaap_GainLossOnSaleOfBusiness" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Gain on disposition of business</link:label>
    <link:label id="lab_us-gaap_GainLossOnSaleOfBusiness_label_en-US" xlink:label="lab_us-gaap_GainLossOnSaleOfBusiness" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Gain (Loss) on Disposition of Business</link:label>
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    <link:label id="lab_srt_ConsolidationItemsAxis_f5a1abd1-7399-4341-aaa1-214f9564e0d9_terseLabel_en-US" xlink:label="lab_srt_ConsolidationItemsAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Consolidation Items</link:label>
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    <link:label id="lab_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_eef8452d-562b-4a2f-9ec5-f4899a4117ae_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table]</link:label>
    <link:label id="lab_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table]</link:label>
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    <link:label id="lab_smlp_PartnersCapitalLineItems_7dda1687-6516-4207-a63c-5a43ee8f30d3_terseLabel_en-US" xlink:label="lab_smlp_PartnersCapitalLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Partners Capital [Line Items]</link:label>
    <link:label id="lab_smlp_PartnersCapitalLineItems_label_en-US" xlink:label="lab_smlp_PartnersCapitalLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Partners Capital [Line Items]</link:label>
    <link:label id="lab_smlp_PartnersCapitalLineItems_documentation_en-US" xlink:label="lab_smlp_PartnersCapitalLineItems" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Partners' capital.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_PartnersCapitalLineItems" xlink:href="smlp-20240331.xsd#smlp_PartnersCapitalLineItems"/>
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    <link:label id="lab_smlp_SeniorUnsecuredNotesDue2026Member_1b552362-4c45-44ff-86e0-7d5a899ec960_terseLabel_en-US" xlink:label="lab_smlp_SeniorUnsecuredNotesDue2026Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2026 Unsecured Notes: $12.00% senior unsecured notes due October 15, 2026</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_smlp_SeniorUnsecuredNotesDue2026Member" xlink:href="smlp-20240331.xsd#smlp_SeniorUnsecuredNotesDue2026Member"/>
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    <link:label id="lab_us-gaap_ScheduleOfStockByClassTable_1d4e2059-33d0-4bce-9ce6-1762b2ae1b51_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfStockByClassTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Stock by Class [Table]</link:label>
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    <link:label id="lab_smlp_SecuredNotesIndenture2026Member_documentation_en-US" xlink:label="lab_smlp_SecuredNotesIndenture2026Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Secured Notes Indenture, 2026</link:label>
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    <link:label id="lab_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_06a980d0-3a4b-4725-97b7-76ae8cb3e461_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Unused portion under the facility</link:label>
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    <link:label id="lab_us-gaap_ShareBasedCompensation_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Payment Arrangement, Noncash Expense</link:label>
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    <link:label id="lab_smlp_ContractWithCustomerLiabilityDisclosureTextBlock_868befd7-aa0e-470d-b523-03e959578663_terseLabel_en-US" xlink:label="lab_smlp_ContractWithCustomerLiabilityDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">DEFERRED REVENUE</link:label>
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    <link:label id="lab_us-gaap_DebtInstrumentRepurchaseAmount_a0a292f5-b737-4245-aec6-5eb0f9497954_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentRepurchaseAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt instrument, repurchase amount</link:label>
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    <link:label id="lab_dei_CityAreaCode_6c270021-6124-46bd-bbe1-70ccc3003de3_terseLabel_en-US" xlink:label="lab_dei_CityAreaCode" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">City Area Code</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_CityAreaCode" xlink:to="lab_dei_CityAreaCode" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_EntityAddressPostalZipCode_83dea215-7917-47a3-96cf-fa3f01518d4c_terseLabel_en-US" xlink:label="lab_dei_EntityAddressPostalZipCode" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Entity Address, Postal Zip Code</link:label>
    <link:label id="lab_dei_EntityAddressPostalZipCode_label_en-US" xlink:label="lab_dei_EntityAddressPostalZipCode" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Address, Postal Zip Code</link:label>
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    <link:label id="lab_us-gaap_EarningsPerShareTextBlock_d8105955-421a-4852-811c-39db86a1e648_terseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerShareTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EARNINGS PER UNIT</link:label>
    <link:label id="lab_us-gaap_EarningsPerShareTextBlock_label_en-US" xlink:label="lab_us-gaap_EarningsPerShareTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Earnings Per Share [Text Block]</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EarningsPerShareTextBlock" xlink:to="lab_us-gaap_EarningsPerShareTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_ProductOrServiceAxis_12554a08-2231-4ab3-9281-0cf2f458ec69_terseLabel_en-US" xlink:label="lab_srt_ProductOrServiceAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Product and Service [Axis]</link:label>
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    <link:label id="lab_us-gaap_RepaymentsOfSecuredDebt_d2bbe743-fb54-4a6d-8cec-f35dcf6123a6_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_RepaymentsOfSecuredDebt" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Repayments on Permian Transmission Term Loan</link:label>
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    <link:label id="lab_us-gaap_EquityMethodInvestmentOwnershipPercentage_4614e211-f365-4425-8fa2-728f82facaa2_terseLabel_en-US" xlink:label="lab_us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Percentage of ownership interest</link:label>
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    <link:label id="lab_us-gaap_PartnersCapitalNotesDisclosureTextBlock_32da3fe9-49c4-4e06-908b-74e34f1bfccb_terseLabel_en-US" xlink:label="lab_us-gaap_PartnersCapitalNotesDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">PARTNERS' CAPITAL AND MEZZANINE CAPITAL</link:label>
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    <link:label id="lab_us-gaap_NetIncomeLossNetOfTaxPerOutstandingLimitedPartnershipUnitDiluted_653130ad-5d42-4b56-9d44-997f0e2e4ce2_terseLabel_en-US" xlink:label="lab_us-gaap_NetIncomeLossNetOfTaxPerOutstandingLimitedPartnershipUnitDiluted" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Common unit - diluted (in dollars per share)</link:label>
    <link:label id="lab_us-gaap_NetIncomeLossNetOfTaxPerOutstandingLimitedPartnershipUnitDiluted_label_en-US" xlink:label="lab_us-gaap_NetIncomeLossNetOfTaxPerOutstandingLimitedPartnershipUnitDiluted" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net Income (Loss), Net of Tax, Per Outstanding Limited Partnership Unit, Diluted</link:label>
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    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentNet_764e5b08-80ef-4267-9bed-a3bf2505c500_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Property, plant and equipment, net</link:label>
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    <link:label id="lab_us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest_label_en-US" xlink:label="lab_us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Partners' Capital, Including Portion Attributable to Noncontrolling Interest</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest" xlink:to="lab_us-gaap_PartnersCapitalIncludingPortionAttributableToNoncontrollingInterest" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_PiceanceBasinSegmentMember_695405f6-4f57-43e1-85ec-c496f5baf330_terseLabel_en-US" xlink:label="lab_smlp_PiceanceBasinSegmentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Piceance</link:label>
    <link:label id="lab_smlp_PiceanceBasinSegmentMember_label_en-US" xlink:label="lab_smlp_PiceanceBasinSegmentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Piceance Basin Segment [Member]</link:label>
    <link:label id="lab_smlp_PiceanceBasinSegmentMember_documentation_en-US" xlink:label="lab_smlp_PiceanceBasinSegmentMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Piceance Basin segment.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_PiceanceBasinSegmentMember" xlink:href="smlp-20240331.xsd#smlp_PiceanceBasinSegmentMember"/>
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    <link:label id="lab_us-gaap_UnsecuredLongTermDebt_6775c159-bb7e-4951-af2c-12c52fd52e20_terseLabel_en-US" xlink:label="lab_us-gaap_UnsecuredLongTermDebt" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Unsecured notes</link:label>
    <link:label id="lab_us-gaap_UnsecuredLongTermDebt_label_en-US" xlink:label="lab_us-gaap_UnsecuredLongTermDebt" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Unsecured Long-Term Debt, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnsecuredLongTermDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_UnsecuredLongTermDebt"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_UnsecuredLongTermDebt" xlink:to="lab_us-gaap_UnsecuredLongTermDebt" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ScheduleOfEnvironmentalLossContingenciesBySiteTextBlock_232d5206-1290-4a29-81cd-7c50e1e588cd_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfEnvironmentalLossContingenciesBySiteTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Accrued Environmental Remediation</link:label>
    <link:label id="lab_us-gaap_ScheduleOfEnvironmentalLossContingenciesBySiteTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfEnvironmentalLossContingenciesBySiteTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Environmental Loss Contingencies by Site [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEnvironmentalLossContingenciesBySiteTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfEnvironmentalLossContingenciesBySiteTextBlock"/>
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    <link:label id="lab_us-gaap_NetIncomeLossAllocatedToLimitedPartners_9a864c00-8617-4612-b7e9-661063004f42_terseLabel_en-US" xlink:label="lab_us-gaap_NetIncomeLossAllocatedToLimitedPartners" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Net income (loss) attributable to common limited partners</link:label>
    <link:label id="lab_us-gaap_NetIncomeLossAllocatedToLimitedPartners_label_en-US" xlink:label="lab_us-gaap_NetIncomeLossAllocatedToLimitedPartners" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net Income (Loss) Allocated to Limited Partners</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAllocatedToLimitedPartners" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossAllocatedToLimitedPartners"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetIncomeLossAllocatedToLimitedPartners" xlink:to="lab_us-gaap_NetIncomeLossAllocatedToLimitedPartners" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DisposalGroupClassificationAxis_2f6ab779-985a-4206-acb2-f97e1981b16e_terseLabel_en-US" xlink:label="lab_us-gaap_DisposalGroupClassificationAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Disposal Group Classification [Axis]</link:label>
    <link:label id="lab_us-gaap_DisposalGroupClassificationAxis_label_en-US" xlink:label="lab_us-gaap_DisposalGroupClassificationAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Disposal Group Classification [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DisposalGroupClassificationAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis" xlink:to="lab_us-gaap_DisposalGroupClassificationAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StatementOfCashFlowsAbstract_bcb260d6-3671-4897-93c5-f4bf5504b062_terseLabel_en-US" xlink:label="lab_us-gaap_StatementOfCashFlowsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Statement of Cash Flows [Abstract]</link:label>
    <link:label id="lab_us-gaap_StatementOfCashFlowsAbstract_label_en-US" xlink:label="lab_us-gaap_StatementOfCashFlowsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statement of Cash Flows [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfCashFlowsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementOfCashFlowsAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementOfCashFlowsAbstract" xlink:to="lab_us-gaap_StatementOfCashFlowsAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccrualForTaxesOtherThanIncomeTaxesCurrent_f484059b-03b1-47fe-8a77-33c6cfa0b974_terseLabel_en-US" xlink:label="lab_us-gaap_AccrualForTaxesOtherThanIncomeTaxesCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Ad valorem taxes payable</link:label>
    <link:label id="lab_us-gaap_AccrualForTaxesOtherThanIncomeTaxesCurrent_label_en-US" xlink:label="lab_us-gaap_AccrualForTaxesOtherThanIncomeTaxesCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accrual for Taxes Other than Income Taxes, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccrualForTaxesOtherThanIncomeTaxesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccrualForTaxesOtherThanIncomeTaxesCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccrualForTaxesOtherThanIncomeTaxesCurrent" xlink:to="lab_us-gaap_AccrualForTaxesOtherThanIncomeTaxesCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AssetsAbstract_a29dee57-e771-43a7-93be-493cbf8e353e_terseLabel_en-US" xlink:label="lab_us-gaap_AssetsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">ASSETS</link:label>
    <link:label id="lab_us-gaap_AssetsAbstract_label_en-US" xlink:label="lab_us-gaap_AssetsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Assets [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetsAbstract" xlink:to="lab_us-gaap_AssetsAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_GainLossOnDispositionOfBusinessNetOfPriorPeriodClassification_f100a224-5c28-43d1-9903-8b464bee23dd_negatedTerseLabel_en-US" xlink:label="lab_smlp_GainLossOnDispositionOfBusinessNetOfPriorPeriodClassification" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Gain on sale of business</link:label>
    <link:label id="lab_smlp_GainLossOnDispositionOfBusinessNetOfPriorPeriodClassification_label_en-US" xlink:label="lab_smlp_GainLossOnDispositionOfBusinessNetOfPriorPeriodClassification" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Gain (Loss) on Disposition of Business, Net of Prior Period Classification</link:label>
    <link:label id="lab_smlp_GainLossOnDispositionOfBusinessNetOfPriorPeriodClassification_documentation_en-US" xlink:label="lab_smlp_GainLossOnDispositionOfBusinessNetOfPriorPeriodClassification" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Gain (Loss) on Disposition of Business, Net of Prior Period Classification</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_GainLossOnDispositionOfBusinessNetOfPriorPeriodClassification" xlink:href="smlp-20240331.xsd#smlp_GainLossOnDispositionOfBusinessNetOfPriorPeriodClassification"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_GainLossOnDispositionOfBusinessNetOfPriorPeriodClassification" xlink:to="lab_smlp_GainLossOnDispositionOfBusinessNetOfPriorPeriodClassification" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_36f63478-acf6-4534-8cb1-fdfe3d9665f4_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Foreign currency (gain) loss</link:label>
    <link:label id="lab_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_label_en-US" xlink:label="lab_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Gain (Loss), Foreign Currency Transaction, before Tax</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ForeignCurrencyTransactionGainLossBeforeTax"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:to="lab_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ProductAndServiceOtherMember_f1db2deb-85a9-463a-b4a4-ca35df2aef6e_terseLabel_en-US" xlink:label="lab_us-gaap_ProductAndServiceOtherMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other revenues</link:label>
    <link:label id="lab_us-gaap_ProductAndServiceOtherMember_32ce15e8-d24f-416e-af01-c6741b0af666_verboseLabel_en-US" xlink:label="lab_us-gaap_ProductAndServiceOtherMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Other revenues</link:label>
    <link:label id="lab_us-gaap_ProductAndServiceOtherMember_label_en-US" xlink:label="lab_us-gaap_ProductAndServiceOtherMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Product and Service, Other [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductAndServiceOtherMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProductAndServiceOtherMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProductAndServiceOtherMember" xlink:to="lab_us-gaap_ProductAndServiceOtherMember" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_DebtInstrumentCovenantInterestCoverageRatio_28fa39ae-eb39-4910-8dc2-c7b2eebe8b75_terseLabel_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantInterestCoverageRatio" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Interest coverage ratio</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantInterestCoverageRatio_label_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantInterestCoverageRatio" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Interest Coverage Ratio</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantInterestCoverageRatio_documentation_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantInterestCoverageRatio" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Interest Coverage Ratio</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_DebtInstrumentCovenantInterestCoverageRatio" xlink:href="smlp-20240331.xsd#smlp_DebtInstrumentCovenantInterestCoverageRatio"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_DebtInstrumentCovenantInterestCoverageRatio" xlink:to="lab_smlp_DebtInstrumentCovenantInterestCoverageRatio" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ProfitLoss_d34a14d1-e69c-413c-8fbb-5922dab04e59_totalLabel_en-US" xlink:label="lab_us-gaap_ProfitLoss" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net income (loss)</link:label>
    <link:label id="lab_us-gaap_ProfitLoss_98410308-17ed-4bfd-8a24-713b226e9a03_terseLabel_en-US" xlink:label="lab_us-gaap_ProfitLoss" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Net income (loss)</link:label>
    <link:label id="lab_us-gaap_ProfitLoss_e4248b0b-3389-406a-9157-65bd0c092d06_verboseLabel_en-US" xlink:label="lab_us-gaap_ProfitLoss" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Net income (loss)</link:label>
    <link:label id="lab_us-gaap_ProfitLoss_label_en-US" xlink:label="lab_us-gaap_ProfitLoss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net Income (Loss), Including Portion Attributable to Noncontrolling Interest</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProfitLoss"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProfitLoss" xlink:to="lab_us-gaap_ProfitLoss" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInFinancingActivities_39dc1d1a-6770-47a1-8302-32c82d625d0b_totalLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net cash used in financing activities</link:label>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInFinancingActivities_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net Cash Provided by (Used in) Financing Activities</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
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    <link:label id="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_1c92ead1-57a6-4ab5-970d-2d37bc5e666c_terseLabel_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">COMMITMENTS AND CONTINGENCIES</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:to="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PaymentsForProceedsFromOtherInvestingActivities_766b5559-038a-4af2-b37b-0ea641fc4cca_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_PaymentsForProceedsFromOtherInvestingActivities" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Other, net</link:label>
    <link:label id="lab_us-gaap_PaymentsForProceedsFromOtherInvestingActivities_label_en-US" xlink:label="lab_us-gaap_PaymentsForProceedsFromOtherInvestingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Payments for (Proceeds from) Other Investing Activities</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForProceedsFromOtherInvestingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsForProceedsFromOtherInvestingActivities"/>
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    <link:label id="lab_us-gaap_LongTermDebtCurrent_ca6d4242-dd32-4d16-a825-3e557997c9f8_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Current portion of long-term debt</link:label>
    <link:label id="lab_us-gaap_LongTermDebtCurrent_91e3c004-2894-48c4-9f0c-ed6ac4eb06d7_negatedLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtCurrent" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Less: current portion of Permian Transmission Term Loan and 2026 Secured Notes tender</link:label>
    <link:label id="lab_us-gaap_LongTermDebtCurrent_label_en-US" xlink:label="lab_us-gaap_LongTermDebtCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Debt, Current Maturities</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtCurrent" xlink:to="lab_us-gaap_LongTermDebtCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LiabilitiesAndStockholdersEquity_e0d11d6b-5477-4578-8513-24dc86baa6f8_totalLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquity" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">TOTAL LIABILITIES AND CAPITAL</link:label>
    <link:label id="lab_us-gaap_LiabilitiesAndStockholdersEquity_label_en-US" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquity" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Liabilities and Equity</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="lab_us-gaap_LiabilitiesAndStockholdersEquity" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherAssetsNoncurrent_f9b94015-55d8-4cc4-9c35-429a9447c463_terseLabel_en-US" xlink:label="lab_us-gaap_OtherAssetsNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other noncurrent assets</link:label>
    <link:label id="lab_us-gaap_OtherAssetsNoncurrent_label_en-US" xlink:label="lab_us-gaap_OtherAssetsNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Assets, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherAssetsNoncurrent" xlink:to="lab_us-gaap_OtherAssetsNoncurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtInstrumentTable_a4eff348-a64b-40cc-9223-038bfb9579fa_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Long-term Debt Instruments [Table]</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentTable_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Long-Term Debt Instruments [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentTable" xlink:to="lab_us-gaap_DebtInstrumentTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccountingPoliciesAbstract_c3c298e3-9150-4ea5-a9ce-4711dbb8d19f_terseLabel_en-US" xlink:label="lab_us-gaap_AccountingPoliciesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accounting Policies [Abstract]</link:label>
    <link:label id="lab_us-gaap_AccountingPoliciesAbstract_label_en-US" xlink:label="lab_us-gaap_AccountingPoliciesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accounting Policies [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountingPoliciesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountingPoliciesAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccountingPoliciesAbstract" xlink:to="lab_us-gaap_AccountingPoliciesAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_GainLossOnDispositionOfAssets1_e5627350-4c5c-4511-95d2-55b9d8192590_negatedLabel_en-US" xlink:label="lab_us-gaap_GainLossOnDispositionOfAssets1" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Gain on asset sales, net</link:label>
    <link:label id="lab_us-gaap_GainLossOnDispositionOfAssets1_9fa8181b-c18a-428c-b4cc-fd81f8fd563e_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_GainLossOnDispositionOfAssets1" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Gain on asset sales, net</link:label>
    <link:label id="lab_us-gaap_GainLossOnDispositionOfAssets1_label_en-US" xlink:label="lab_us-gaap_GainLossOnDispositionOfAssets1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Gain (Loss) on Disposition of Assets</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnDispositionOfAssets1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GainLossOnDispositionOfAssets1"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GainLossOnDispositionOfAssets1" xlink:to="lab_us-gaap_GainLossOnDispositionOfAssets1" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_OhioGatheringCompanyLLCMember_09616e6e-4926-41dc-96f7-af2833c93523_verboseLabel_en-US" xlink:label="lab_smlp_OhioGatheringCompanyLLCMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">OGC</link:label>
    <link:label id="lab_smlp_OhioGatheringCompanyLLCMember_f172a1e8-8af5-4e77-8033-cb52383a49de_terseLabel_en-US" xlink:label="lab_smlp_OhioGatheringCompanyLLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Ohio Gathering</link:label>
    <link:label id="lab_smlp_OhioGatheringCompanyLLCMember_label_en-US" xlink:label="lab_smlp_OhioGatheringCompanyLLCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Ohio Gathering Company L L C [Member]</link:label>
    <link:label id="lab_smlp_OhioGatheringCompanyLLCMember_documentation_en-US" xlink:label="lab_smlp_OhioGatheringCompanyLLCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Ohio Gathering Company, L.L.C.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_OhioGatheringCompanyLLCMember" xlink:href="smlp-20240331.xsd#smlp_OhioGatheringCompanyLLCMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_OhioGatheringCompanyLLCMember" xlink:to="lab_smlp_OhioGatheringCompanyLLCMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OilAndCondensateMember_7b74a877-1c70-4a72-aeb1-d77d7c1c1b1c_terseLabel_en-US" xlink:label="lab_us-gaap_OilAndCondensateMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Natural gas, NGLs and condensate sales</link:label>
    <link:label id="lab_us-gaap_OilAndCondensateMember_label_en-US" xlink:label="lab_us-gaap_OilAndCondensateMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Oil and Condensate [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OilAndCondensateMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OilAndCondensateMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OilAndCondensateMember" xlink:to="lab_us-gaap_OilAndCondensateMember" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_ScheduleOfPartnerUnitsActivityTableTableTextBlock_67ed09cf-5d52-413d-8b7c-f0c51793c055_terseLabel_en-US" xlink:label="lab_smlp_ScheduleOfPartnerUnitsActivityTableTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule Of Partner Units Activity</link:label>
    <link:label id="lab_smlp_ScheduleOfPartnerUnitsActivityTableTableTextBlock_label_en-US" xlink:label="lab_smlp_ScheduleOfPartnerUnitsActivityTableTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule Of Partner Units Activity Table [Table Text Block]</link:label>
    <link:label id="lab_smlp_ScheduleOfPartnerUnitsActivityTableTableTextBlock_documentation_en-US" xlink:label="lab_smlp_ScheduleOfPartnerUnitsActivityTableTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Schedule of partner units activity.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_ScheduleOfPartnerUnitsActivityTableTableTextBlock" xlink:href="smlp-20240331.xsd#smlp_ScheduleOfPartnerUnitsActivityTableTableTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_ScheduleOfPartnerUnitsActivityTableTableTextBlock" xlink:to="lab_smlp_ScheduleOfPartnerUnitsActivityTableTableTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_EntityAddressCityOrTown_b2143e31-3d20-4e80-b83e-68b0eea00efc_terseLabel_en-US" xlink:label="lab_dei_EntityAddressCityOrTown" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Entity Address, City or Town</link:label>
    <link:label id="lab_dei_EntityAddressCityOrTown_label_en-US" xlink:label="lab_dei_EntityAddressCityOrTown" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Address, City or Town</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressCityOrTown"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityAddressCityOrTown" xlink:to="lab_dei_EntityAddressCityOrTown" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ConsolidationPolicyTextBlock_a0131869-c3a8-4481-8534-be770261efa3_terseLabel_en-US" xlink:label="lab_us-gaap_ConsolidationPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Consolidation</link:label>
    <link:label id="lab_us-gaap_ConsolidationPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_ConsolidationPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Consolidation, Policy [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsolidationPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConsolidationPolicyTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConsolidationPolicyTextBlock" xlink:to="lab_us-gaap_ConsolidationPolicyTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_DocumentTransitionReport_a2a4c16a-6ea6-4fcb-bf23-bf1aafa6cb35_terseLabel_en-US" xlink:label="lab_dei_DocumentTransitionReport" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Document Transition Report</link:label>
    <link:label id="lab_dei_DocumentTransitionReport_label_en-US" xlink:label="lab_dei_DocumentTransitionReport" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Transition Report</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentTransitionReport"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentTransitionReport" xlink:to="lab_dei_DocumentTransitionReport" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_UnsecuredDebtMember_f7fc2df9-6367-49b5-9368-49b5e15dc88e_terseLabel_en-US" xlink:label="lab_us-gaap_UnsecuredDebtMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Unsecured Debt</link:label>
    <link:label id="lab_us-gaap_UnsecuredDebtMember_label_en-US" xlink:label="lab_us-gaap_UnsecuredDebtMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Unsecured Debt [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnsecuredDebtMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_UnsecuredDebtMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_UnsecuredDebtMember" xlink:to="lab_us-gaap_UnsecuredDebtMember" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_DepreciationDepletionAndAmortizationIncludingAmortizationOfAboveAndBelowMarketLeases_bc4942d0-678d-4b21-b261-d6ca4298dd3d_terseLabel_en-US" xlink:label="lab_smlp_DepreciationDepletionAndAmortizationIncludingAmortizationOfAboveAndBelowMarketLeases" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Depreciation and amortization</link:label>
    <link:label id="lab_smlp_DepreciationDepletionAndAmortizationIncludingAmortizationOfAboveAndBelowMarketLeases_label_en-US" xlink:label="lab_smlp_DepreciationDepletionAndAmortizationIncludingAmortizationOfAboveAndBelowMarketLeases" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Depreciation Depletion And Amortization Including Amortization Of Above And Below Market Leases</link:label>
    <link:label id="lab_smlp_DepreciationDepletionAndAmortizationIncludingAmortizationOfAboveAndBelowMarketLeases_documentation_en-US" xlink:label="lab_smlp_DepreciationDepletionAndAmortizationIncludingAmortizationOfAboveAndBelowMarketLeases" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Depreciation depletion and amortization including amortization of above and below market leases.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_DepreciationDepletionAndAmortizationIncludingAmortizationOfAboveAndBelowMarketLeases" xlink:href="smlp-20240331.xsd#smlp_DepreciationDepletionAndAmortizationIncludingAmortizationOfAboveAndBelowMarketLeases"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_DepreciationDepletionAndAmortizationIncludingAmortizationOfAboveAndBelowMarketLeases" xlink:to="lab_smlp_DepreciationDepletionAndAmortizationIncludingAmortizationOfAboveAndBelowMarketLeases" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentAbstract_86022df9-fa25-4d67-866d-a3ad40c92e99_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment [Abstract]</link:label>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentAbstract_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DerivativeInstrumentRiskAxis_fda972df-69e9-4a29-8ffb-53080313b1f9_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeInstrumentRiskAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Derivative Instrument</link:label>
    <link:label id="lab_us-gaap_DerivativeInstrumentRiskAxis_label_en-US" xlink:label="lab_us-gaap_DerivativeInstrumentRiskAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative Instrument [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis" xlink:to="lab_us-gaap_DerivativeInstrumentRiskAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PhantomShareUnitsPSUsMember_568f0156-bb6e-4c33-93a0-4f2971be40a4_terseLabel_en-US" xlink:label="lab_us-gaap_PhantomShareUnitsPSUsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Phantom Units</link:label>
    <link:label id="lab_us-gaap_PhantomShareUnitsPSUsMember_label_en-US" xlink:label="lab_us-gaap_PhantomShareUnitsPSUsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Phantom Share Units (PSUs) [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PhantomShareUnitsPSUsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PhantomShareUnitsPSUsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PhantomShareUnitsPSUsMember" xlink:to="lab_us-gaap_PhantomShareUnitsPSUsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtInstrumentCarryingAmount_082cf233-c171-45c7-9546-b0d44f49229e_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentCarryingAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Term loan</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentCarryingAmount_3f05e5ae-78fd-491a-b1e3-083b8f8c1404_totalLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentCarryingAmount" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Amortizing principal repayments</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentCarryingAmount_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentCarryingAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Debt, Gross</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentCarryingAmount" xlink:to="lab_us-gaap_DebtInstrumentCarryingAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_SeriesAPreferredUnitsMember_48b6678f-ae71-4b50-ba8d-3a4439f1fc70_terseLabel_en-US" xlink:label="lab_smlp_SeriesAPreferredUnitsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Series A Preferred Units</link:label>
    <link:label id="lab_smlp_SeriesAPreferredUnitsMember_label_en-US" xlink:label="lab_smlp_SeriesAPreferredUnitsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Series A Preferred Units [Member]</link:label>
    <link:label id="lab_smlp_SeriesAPreferredUnitsMember_documentation_en-US" xlink:label="lab_smlp_SeriesAPreferredUnitsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Series A preferred units.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_SeriesAPreferredUnitsMember" xlink:href="smlp-20240331.xsd#smlp_SeriesAPreferredUnitsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_SeriesAPreferredUnitsMember" xlink:to="lab_smlp_SeriesAPreferredUnitsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_e5bda700-535a-48b9-a419-5debc39744a7_terseLabel_en-US" xlink:label="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Adjustments to reconcile net loss to net cash provided by operating activities:</link:label>
    <link:label id="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_label_en-US" xlink:label="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_AccrualForEnvironmentalLossContingenciesExpectedPayment_05682f50-3f88-4bce-ade2-5c6dd37ed8a6_terseLabel_en-US" xlink:label="lab_smlp_AccrualForEnvironmentalLossContingenciesExpectedPayment" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Expected payment</link:label>
    <link:label id="lab_smlp_AccrualForEnvironmentalLossContingenciesExpectedPayment_label_en-US" xlink:label="lab_smlp_AccrualForEnvironmentalLossContingenciesExpectedPayment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accrual for Environmental Loss Contingencies, Expected Payment</link:label>
    <link:label id="lab_smlp_AccrualForEnvironmentalLossContingenciesExpectedPayment_documentation_en-US" xlink:label="lab_smlp_AccrualForEnvironmentalLossContingenciesExpectedPayment" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Accrual for Environmental Loss Contingencies, Expected Payment</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_AccrualForEnvironmentalLossContingenciesExpectedPayment" xlink:href="smlp-20240331.xsd#smlp_AccrualForEnvironmentalLossContingenciesExpectedPayment"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_AccrualForEnvironmentalLossContingenciesExpectedPayment" xlink:to="lab_smlp_AccrualForEnvironmentalLossContingenciesExpectedPayment" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_MeadowlarkMidstreamGatheringSystemMember_a6a19731-0ccb-4028-b2eb-bbb2478f7776_terseLabel_en-US" xlink:label="lab_smlp_MeadowlarkMidstreamGatheringSystemMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Meadowlark Midstream Gathering System</link:label>
    <link:label id="lab_smlp_MeadowlarkMidstreamGatheringSystemMember_label_en-US" xlink:label="lab_smlp_MeadowlarkMidstreamGatheringSystemMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Meadowlark Midstream Gathering System [Member]</link:label>
    <link:label id="lab_smlp_MeadowlarkMidstreamGatheringSystemMember_documentation_en-US" xlink:label="lab_smlp_MeadowlarkMidstreamGatheringSystemMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Meadowlark Midstream gathering system.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_MeadowlarkMidstreamGatheringSystemMember" xlink:href="smlp-20240331.xsd#smlp_MeadowlarkMidstreamGatheringSystemMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_MeadowlarkMidstreamGatheringSystemMember" xlink:to="lab_smlp_MeadowlarkMidstreamGatheringSystemMember" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_AssetBackedLendingFacilityMember_cd0a57d2-172e-428a-abe2-0da5fb376ad6_terseLabel_en-US" xlink:label="lab_smlp_AssetBackedLendingFacilityMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">ABL Facility: Summit Holdings' asset based credit facility due May 1, 2026</link:label>
    <link:label id="lab_smlp_AssetBackedLendingFacilityMember_label_en-US" xlink:label="lab_smlp_AssetBackedLendingFacilityMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Asset Backed Lending Facility [Member]</link:label>
    <link:label id="lab_smlp_AssetBackedLendingFacilityMember_documentation_en-US" xlink:label="lab_smlp_AssetBackedLendingFacilityMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Asset Backed Lending Facility</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_AssetBackedLendingFacilityMember" xlink:href="smlp-20240331.xsd#smlp_AssetBackedLendingFacilityMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_AssetBackedLendingFacilityMember" xlink:to="lab_smlp_AssetBackedLendingFacilityMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LimitedPartnersCapitalAccount_3b6f68cb-1d8d-40fe-9d9b-8de11dd03878_terseLabel_en-US" xlink:label="lab_us-gaap_LimitedPartnersCapitalAccount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Common limited partner capital (10,648,685 and 10,376,189 units issued and outstanding at March&#160;31, 2024 and December&#160;31, 2023, respectively)</link:label>
    <link:label id="lab_us-gaap_LimitedPartnersCapitalAccount_label_en-US" xlink:label="lab_us-gaap_LimitedPartnersCapitalAccount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Limited Partners' Capital Account</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LimitedPartnersCapitalAccount" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LimitedPartnersCapitalAccount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LimitedPartnersCapitalAccount" xlink:to="lab_us-gaap_LimitedPartnersCapitalAccount" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTableTextBlock_86f8ba59-12f3-41dc-8869-56d7659ba196_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Estimated Revenue Expected to be Recognized and MVC Shortfall Payments</link:label>
    <link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTableTextBlock_label_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTableTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTableTextBlock" xlink:to="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTableTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ReconciliationOfAssetsFromSegmentToConsolidatedTextBlock_6f7974f0-58ec-453f-a5c6-bbffcdebee3f_terseLabel_en-US" xlink:label="lab_us-gaap_ReconciliationOfAssetsFromSegmentToConsolidatedTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Reconciliation of Assets from Segment to Consolidated</link:label>
    <link:label id="lab_us-gaap_ReconciliationOfAssetsFromSegmentToConsolidatedTextBlock_label_en-US" xlink:label="lab_us-gaap_ReconciliationOfAssetsFromSegmentToConsolidatedTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Reconciliation of Assets from Segment to Consolidated [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReconciliationOfAssetsFromSegmentToConsolidatedTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ReconciliationOfAssetsFromSegmentToConsolidatedTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ReconciliationOfAssetsFromSegmentToConsolidatedTextBlock" xlink:to="lab_us-gaap_ReconciliationOfAssetsFromSegmentToConsolidatedTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_PermianTransmissionTermLoanMember_5f32ab88-c692-4fd4-accd-22fe9555ddde_terseLabel_en-US" xlink:label="lab_smlp_PermianTransmissionTermLoanMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Permian Transmission Term Loan: Summit Permian Transmission's variable rate senior secured term loan due January 2028</link:label>
    <link:label id="lab_smlp_PermianTransmissionTermLoanMember_label_en-US" xlink:label="lab_smlp_PermianTransmissionTermLoanMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Permian Transmission Term Loan [Member]</link:label>
    <link:label id="lab_smlp_PermianTransmissionTermLoanMember_documentation_en-US" xlink:label="lab_smlp_PermianTransmissionTermLoanMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Permian Transmission Term Loan</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_PermianTransmissionTermLoanMember" xlink:href="smlp-20240331.xsd#smlp_PermianTransmissionTermLoanMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_PermianTransmissionTermLoanMember" xlink:to="lab_smlp_PermianTransmissionTermLoanMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount_f7fcb255-e6b9-43f0-adcd-fbfba198be3b_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Unused portion of the permian transmission credit facility</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Unused Borrowing Capacity, Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount" xlink:to="lab_us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SubsequentEventTypeAxis_2edf9632-e7ec-486f-bf8a-0fe69cd7ef72_terseLabel_en-US" xlink:label="lab_us-gaap_SubsequentEventTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Subsequent Event Type</link:label>
    <link:label id="lab_us-gaap_SubsequentEventTypeAxis_label_en-US" xlink:label="lab_us-gaap_SubsequentEventTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Subsequent Event Type [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventTypeAxis" xlink:to="lab_us-gaap_SubsequentEventTypeAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_ReconciliationOfNetIncomeToAdjustedEBITDATableTableTextBlock_fed91b92-fe95-4ee6-8253-2dcf04b9ab9e_terseLabel_en-US" xlink:label="lab_smlp_ReconciliationOfNetIncomeToAdjustedEBITDATableTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Reconciliation of Net Income to Adjusted EBITDA</link:label>
    <link:label id="lab_smlp_ReconciliationOfNetIncomeToAdjustedEBITDATableTableTextBlock_label_en-US" xlink:label="lab_smlp_ReconciliationOfNetIncomeToAdjustedEBITDATableTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Reconciliation Of Net Income To Adjusted E B I T D A Table [Table Text Block]</link:label>
    <link:label id="lab_smlp_ReconciliationOfNetIncomeToAdjustedEBITDATableTableTextBlock_documentation_en-US" xlink:label="lab_smlp_ReconciliationOfNetIncomeToAdjustedEBITDATableTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Reconciliation of net income to adjusted EBITDA.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_ReconciliationOfNetIncomeToAdjustedEBITDATableTableTextBlock" xlink:href="smlp-20240331.xsd#smlp_ReconciliationOfNetIncomeToAdjustedEBITDATableTableTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_ReconciliationOfNetIncomeToAdjustedEBITDATableTableTextBlock" xlink:to="lab_smlp_ReconciliationOfNetIncomeToAdjustedEBITDATableTableTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NetIncomeLossPerOutstandingLimitedPartnershipUnitBasicNetOfTax_0b76ecd9-59c8-4b10-a39b-c36d5e41efa9_terseLabel_en-US" xlink:label="lab_us-gaap_NetIncomeLossPerOutstandingLimitedPartnershipUnitBasicNetOfTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Common unit - basic (in dollars per share)</link:label>
    <link:label id="lab_us-gaap_NetIncomeLossPerOutstandingLimitedPartnershipUnitBasicNetOfTax_label_en-US" xlink:label="lab_us-gaap_NetIncomeLossPerOutstandingLimitedPartnershipUnitBasicNetOfTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net Income (Loss), Per Outstanding Limited Partnership Unit, Basic, Net of Tax</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossPerOutstandingLimitedPartnershipUnitBasicNetOfTax" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossPerOutstandingLimitedPartnershipUnitBasicNetOfTax"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetIncomeLossPerOutstandingLimitedPartnershipUnitBasicNetOfTax" xlink:to="lab_us-gaap_NetIncomeLossPerOutstandingLimitedPartnershipUnitBasicNetOfTax" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_ChangeInContractWithCustomerLiabilityCurrentRollForward_bce1fb96-ff05-4bfa-be59-a711293a5fb7_terseLabel_en-US" xlink:label="lab_smlp_ChangeInContractWithCustomerLiabilityCurrentRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Change in Contract with Customer, Liability, Current [Roll Forward]</link:label>
    <link:label id="lab_smlp_ChangeInContractWithCustomerLiabilityCurrentRollForward_label_en-US" xlink:label="lab_smlp_ChangeInContractWithCustomerLiabilityCurrentRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Change in Contract with Customer, Liability, Current [Roll Forward]</link:label>
    <link:label id="lab_smlp_ChangeInContractWithCustomerLiabilityCurrentRollForward_documentation_en-US" xlink:label="lab_smlp_ChangeInContractWithCustomerLiabilityCurrentRollForward" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Change in Contract with Customer, Liability, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_ChangeInContractWithCustomerLiabilityCurrentRollForward" xlink:href="smlp-20240331.xsd#smlp_ChangeInContractWithCustomerLiabilityCurrentRollForward"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_ChangeInContractWithCustomerLiabilityCurrentRollForward" xlink:to="lab_smlp_ChangeInContractWithCustomerLiabilityCurrentRollForward" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CashFlowSupplementalDisclosuresTextBlock_f92a43c1-c19a-4b09-8a8e-733391b4bc20_terseLabel_en-US" xlink:label="lab_us-gaap_CashFlowSupplementalDisclosuresTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">SUPPLEMENTAL CASH FLOW INFORMATION</link:label>
    <link:label id="lab_us-gaap_CashFlowSupplementalDisclosuresTextBlock_label_en-US" xlink:label="lab_us-gaap_CashFlowSupplementalDisclosuresTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash Flow, Supplemental Disclosures [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFlowSupplementalDisclosuresTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashFlowSupplementalDisclosuresTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CashFlowSupplementalDisclosuresTextBlock" xlink:to="lab_us-gaap_CashFlowSupplementalDisclosuresTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_DebtInstrumentCovenantRedemptionPercentOfInitialPrincipalAmountRemainingOutstanding_2b028983-d6e6-48f9-bde2-58946f45aaa1_terseLabel_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantRedemptionPercentOfInitialPrincipalAmountRemainingOutstanding" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Redemption, Percent of Initial Principal Amount Remaining Outstanding</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantRedemptionPercentOfInitialPrincipalAmountRemainingOutstanding_label_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantRedemptionPercentOfInitialPrincipalAmountRemainingOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Redemption, Percent of Initial Principal Amount Remaining Outstanding</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantRedemptionPercentOfInitialPrincipalAmountRemainingOutstanding_documentation_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantRedemptionPercentOfInitialPrincipalAmountRemainingOutstanding" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Redemption, Percent of Initial Principal Amount Remaining Outstanding</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_DebtInstrumentCovenantRedemptionPercentOfInitialPrincipalAmountRemainingOutstanding" xlink:href="smlp-20240331.xsd#smlp_DebtInstrumentCovenantRedemptionPercentOfInitialPrincipalAmountRemainingOutstanding"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_DebtInstrumentCovenantRedemptionPercentOfInitialPrincipalAmountRemainingOutstanding" xlink:to="lab_smlp_DebtInstrumentCovenantRedemptionPercentOfInitialPrincipalAmountRemainingOutstanding" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtInstrumentRedemptionPeriodDomain_69d3c62f-687b-469a-9320-d57e56206efb_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentRedemptionPeriodDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt Instrument, Redemption, Period</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentRedemptionPeriodDomain_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentRedemptionPeriodDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Redemption, Period [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentRedemptionPeriodDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain" xlink:to="lab_us-gaap_DebtInstrumentRedemptionPeriodDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_SubsidiarySeriesAPreferredUnitsMember_5efc7461-1e60-4288-862b-d1ae943ee122_terseLabel_en-US" xlink:label="lab_smlp_SubsidiarySeriesAPreferredUnitsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Subsidiary Series A Preferred Units</link:label>
    <link:label id="lab_smlp_SubsidiarySeriesAPreferredUnitsMember_label_en-US" xlink:label="lab_smlp_SubsidiarySeriesAPreferredUnitsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Subsidiary Series A Preferred Units [Member]</link:label>
    <link:label id="lab_smlp_SubsidiarySeriesAPreferredUnitsMember_documentation_en-US" xlink:label="lab_smlp_SubsidiarySeriesAPreferredUnitsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Subsidiary Series A Preferred Units</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_SubsidiarySeriesAPreferredUnitsMember" xlink:href="smlp-20240331.xsd#smlp_SubsidiarySeriesAPreferredUnitsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_SubsidiarySeriesAPreferredUnitsMember" xlink:to="lab_smlp_SubsidiarySeriesAPreferredUnitsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_45f6c692-16e0-444b-bb39-97d83b989cce_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2025</link:label>
    <link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_label_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Debt, Maturity, Year One</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:to="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccrualForEnvironmentalLossContingenciesChargesToExpenseForNewLosses_e44fe530-42c8-4f14-a73d-3abf8123fc0d_terseLabel_en-US" xlink:label="lab_us-gaap_AccrualForEnvironmentalLossContingenciesChargesToExpenseForNewLosses" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Legal fines and other fees</link:label>
    <link:label id="lab_us-gaap_AccrualForEnvironmentalLossContingenciesChargesToExpenseForNewLosses_label_en-US" xlink:label="lab_us-gaap_AccrualForEnvironmentalLossContingenciesChargesToExpenseForNewLosses" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accrual for Environmental Loss Contingencies, Charges to Expense for New Losses</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccrualForEnvironmentalLossContingenciesChargesToExpenseForNewLosses" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccrualForEnvironmentalLossContingenciesChargesToExpenseForNewLosses"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccrualForEnvironmentalLossContingenciesChargesToExpenseForNewLosses" xlink:to="lab_us-gaap_AccrualForEnvironmentalLossContingenciesChargesToExpenseForNewLosses" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_PermianBasinSegmentMember_eceed0d0-6a2d-4368-860d-1ea90fb3aadc_terseLabel_en-US" xlink:label="lab_smlp_PermianBasinSegmentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Permian</link:label>
    <link:label id="lab_smlp_PermianBasinSegmentMember_label_en-US" xlink:label="lab_smlp_PermianBasinSegmentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Permian Basin Segment [Member]</link:label>
    <link:label id="lab_smlp_PermianBasinSegmentMember_documentation_en-US" xlink:label="lab_smlp_PermianBasinSegmentMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Permian Basin segment member.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_PermianBasinSegmentMember" xlink:href="smlp-20240331.xsd#smlp_PermianBasinSegmentMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_PermianBasinSegmentMember" xlink:to="lab_smlp_PermianBasinSegmentMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_08d041b7-e590-4d5d-be7c-78aedf0f7779_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Segment Reporting Information, by Segment [Table]</link:label>
    <link:label id="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Segment Reporting Information, by Segment [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:to="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtInstrumentRedemptionPeriodOneMember_e9b90e68-d8f0-4c4f-a6b1-4091720033b2_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentRedemptionPeriodOneMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Beginning October 15, 2023</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentRedemptionPeriodOneMember_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentRedemptionPeriodOneMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Redemption, Period One [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodOneMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentRedemptionPeriodOneMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodOneMember" xlink:to="lab_us-gaap_DebtInstrumentRedemptionPeriodOneMember" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_RockiesSegmentMember_7d052462-32d6-4499-af5b-05afee845373_terseLabel_en-US" xlink:label="lab_smlp_RockiesSegmentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Rockies</link:label>
    <link:label id="lab_smlp_RockiesSegmentMember_label_en-US" xlink:label="lab_smlp_RockiesSegmentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Rockies Segment [Member]</link:label>
    <link:label id="lab_smlp_RockiesSegmentMember_documentation_en-US" xlink:label="lab_smlp_RockiesSegmentMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Rockies Segment</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_RockiesSegmentMember" xlink:href="smlp-20240331.xsd#smlp_RockiesSegmentMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_RockiesSegmentMember" xlink:to="lab_smlp_RockiesSegmentMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AllOtherSegmentsMember_e1cfd65d-f1d4-419e-8672-2b5a8e6af436_terseLabel_en-US" xlink:label="lab_us-gaap_AllOtherSegmentsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Corporate and other</link:label>
    <link:label id="lab_us-gaap_AllOtherSegmentsMember_label_en-US" xlink:label="lab_us-gaap_AllOtherSegmentsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Segments [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllOtherSegmentsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AllOtherSegmentsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AllOtherSegmentsMember" xlink:to="lab_us-gaap_AllOtherSegmentsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_EntityRegistrantName_8c9ddeac-c7f8-4a18-9a60-0829e30dd2ac_terseLabel_en-US" xlink:label="lab_dei_EntityRegistrantName" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Entity Registrant Name</link:label>
    <link:label id="lab_dei_EntityRegistrantName_label_en-US" xlink:label="lab_dei_EntityRegistrantName" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Registrant Name</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityRegistrantName"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityRegistrantName" xlink:to="lab_dei_EntityRegistrantName" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_dfde4745-2880-4bfb-8611-87d6cd7e7340_terseLabel_en-US" xlink:label="lab_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Effect of nonvested phantom units (in shares)</link:label>
    <link:label id="lab_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_label_en-US" xlink:label="lab_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:to="lab_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PreferredStockAccretionOfRedemptionDiscount_e7393a80-b095-47ec-8e96-17b371b15a68_terseLabel_en-US" xlink:label="lab_us-gaap_PreferredStockAccretionOfRedemptionDiscount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Redemption accretion, net of issuance cost amortization</link:label>
    <link:label id="lab_us-gaap_PreferredStockAccretionOfRedemptionDiscount_efb5eb98-41b9-49b7-a203-a49549587a82_verboseLabel_en-US" xlink:label="lab_us-gaap_PreferredStockAccretionOfRedemptionDiscount" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Accretion of Subsidiary Series A Preferred Units, net of issuance cost amortization</link:label>
    <link:label id="lab_us-gaap_PreferredStockAccretionOfRedemptionDiscount_label_en-US" xlink:label="lab_us-gaap_PreferredStockAccretionOfRedemptionDiscount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Preferred Stock, Accretion of Redemption Discount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockAccretionOfRedemptionDiscount" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockAccretionOfRedemptionDiscount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredStockAccretionOfRedemptionDiscount" xlink:to="lab_us-gaap_PreferredStockAccretionOfRedemptionDiscount" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccrualForEnvironmentalLossContingencies_9bcbe00f-75d2-4c15-ab32-42b2fb28ed8e_periodStartLabel_en-US" xlink:label="lab_us-gaap_AccrualForEnvironmentalLossContingencies" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Accrued environmental remediation, beginning balance</link:label>
    <link:label id="lab_us-gaap_AccrualForEnvironmentalLossContingencies_ab549af4-d369-4fc9-995e-7924acc2c3d9_periodEndLabel_en-US" xlink:label="lab_us-gaap_AccrualForEnvironmentalLossContingencies" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Accrued environmental remediation, ending balance</link:label>
    <link:label id="lab_us-gaap_AccrualForEnvironmentalLossContingencies_label_en-US" xlink:label="lab_us-gaap_AccrualForEnvironmentalLossContingencies" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accrual for Environmental Loss Contingencies</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccrualForEnvironmentalLossContingencies" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccrualForEnvironmentalLossContingencies"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccrualForEnvironmentalLossContingencies" xlink:to="lab_us-gaap_AccrualForEnvironmentalLossContingencies" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PartnersCapitalAbstract_8175893c-7d2a-4c95-b38e-92776fc665c9_terseLabel_en-US" xlink:label="lab_us-gaap_PartnersCapitalAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Partners' Capital</link:label>
    <link:label id="lab_us-gaap_PartnersCapitalAbstract_label_en-US" xlink:label="lab_us-gaap_PartnersCapitalAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Partners' Capital [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PartnersCapitalAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PartnersCapitalAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PartnersCapitalAbstract" xlink:to="lab_us-gaap_PartnersCapitalAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PartnersCapitalAccountUnitsUnitbasedCompensation_8e273f9f-31aa-4397-a258-b4c1021e592c_terseLabel_en-US" xlink:label="lab_us-gaap_PartnersCapitalAccountUnitsUnitbasedCompensation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Common units issued for SMLP LTIP, net (in shares)</link:label>
    <link:label id="lab_us-gaap_PartnersCapitalAccountUnitsUnitbasedCompensation_label_en-US" xlink:label="lab_us-gaap_PartnersCapitalAccountUnitsUnitbasedCompensation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Partners' Capital Account, Unit-Based Payment Arrangement, Number of Units</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PartnersCapitalAccountUnitsUnitbasedCompensation" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PartnersCapitalAccountUnitsUnitbasedCompensation"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PartnersCapitalAccountUnitsUnitbasedCompensation" xlink:to="lab_us-gaap_PartnersCapitalAccountUnitsUnitbasedCompensation" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_NortheastSegmentMember_6881cc65-8003-4562-8b90-bab6bd4bf841_terseLabel_en-US" xlink:label="lab_smlp_NortheastSegmentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Northeast</link:label>
    <link:label id="lab_smlp_NortheastSegmentMember_label_en-US" xlink:label="lab_smlp_NortheastSegmentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Northeast Segment [Member]</link:label>
    <link:label id="lab_smlp_NortheastSegmentMember_documentation_en-US" xlink:label="lab_smlp_NortheastSegmentMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Northeast Segment</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_NortheastSegmentMember" xlink:href="smlp-20240331.xsd#smlp_NortheastSegmentMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_NortheastSegmentMember" xlink:to="lab_smlp_NortheastSegmentMember" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_DocumentPeriodEndDate_a13ea805-4c09-4d5c-83fc-64aacfd7b808_verboseLabel_en-US" xlink:label="lab_dei_DocumentPeriodEndDate" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Document Period End Date</link:label>
    <link:label id="lab_dei_DocumentPeriodEndDate_label_en-US" xlink:label="lab_dei_DocumentPeriodEndDate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Period End Date</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentPeriodEndDate"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentPeriodEndDate" xlink:to="lab_dei_DocumentPeriodEndDate" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain_047fc9da-10a4-481f-a899-4fd1d33d9f31_terseLabel_en-US" xlink:label="lab_us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Partner Type of Partners' Capital Account, Name</link:label>
    <link:label id="lab_us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain_label_en-US" xlink:label="lab_us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Partner Type of Partners' Capital Account, Name [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain" xlink:to="lab_us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_8bbe0b18-cbf5-4b78-8c16-a107d510339d_negatedLabel_en-US" xlink:label="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Less: accumulated depreciation</link:label>
    <link:label id="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_label_en-US" xlink:label="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyAccrualAtCarryingValue" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LossContingencyAccrualAtCarryingValue"/>
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    <link:label id="lab_smlp_ABLFacilityMember_a0d9bf4e-3a83-46a7-aaad-565e8474a25f_terseLabel_en-US" xlink:label="lab_smlp_ABLFacilityMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">ABL Facility</link:label>
    <link:label id="lab_smlp_ABLFacilityMember_label_en-US" xlink:label="lab_smlp_ABLFacilityMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">ABL Facility [Member]</link:label>
    <link:label id="lab_smlp_ABLFacilityMember_documentation_en-US" xlink:label="lab_smlp_ABLFacilityMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">ABL Facility</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_ABLFacilityMember" xlink:href="smlp-20240331.xsd#smlp_ABLFacilityMember"/>
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    <link:label id="lab_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_21363f3a-9b41-4fcb-b575-58e4059998f6_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Total revenues</link:label>
    <link:label id="lab_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_label_en-US" xlink:label="lab_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenue from Contract with Customer, Excluding Assessed Tax</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
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    <link:label id="lab_dei_EntityDomain_df80ed87-9171-4c5e-ac8b-facceab383a0_terseLabel_en-US" xlink:label="lab_dei_EntityDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Entity</link:label>
    <link:label id="lab_dei_EntityDomain_label_en-US" xlink:label="lab_dei_EntityDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
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    <link:label id="lab_us-gaap_LongtermDebtTypeAxis_5f35f455-2eb2-4a5c-a37d-215a2a2ce2ad_terseLabel_en-US" xlink:label="lab_us-gaap_LongtermDebtTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Long-term Debt, Type</link:label>
    <link:label id="lab_us-gaap_LongtermDebtTypeAxis_label_en-US" xlink:label="lab_us-gaap_LongtermDebtTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Debt, Type [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongtermDebtTypeAxis" xlink:to="lab_us-gaap_LongtermDebtTypeAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_AmendmentFlag_a9f63287-b8f2-49ed-a1fc-2a58f22aa2b6_terseLabel_en-US" xlink:label="lab_dei_AmendmentFlag" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Amendment Flag</link:label>
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    <link:label id="lab_us-gaap_TemporaryEquitySharesOutstanding_94bd40f9-7fd4-400a-b75e-9e170b468f50_terseLabel_en-US" xlink:label="lab_us-gaap_TemporaryEquitySharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Series A Preferred Units Outstanding (in shares)</link:label>
    <link:label id="lab_us-gaap_TemporaryEquitySharesOutstanding_label_en-US" xlink:label="lab_us-gaap_TemporaryEquitySharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Temporary Equity, Shares Outstanding</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquitySharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquitySharesOutstanding"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_TemporaryEquitySharesOutstanding" xlink:to="lab_us-gaap_TemporaryEquitySharesOutstanding" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_LegalEntityAxis_73bb32b4-b6b8-4d10-b98c-ce339e915c38_terseLabel_en-US" xlink:label="lab_dei_LegalEntityAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Legal Entity</link:label>
    <link:label id="lab_dei_LegalEntityAxis_label_en-US" xlink:label="lab_dei_LegalEntityAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Legal Entity [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_LegalEntityAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_LegalEntityAxis" xlink:to="lab_dei_LegalEntityAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_UnrealizedGainLossOnDerivatives_d8661cb7-45dc-4aa6-9a1d-d1dc84de4d2b_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_UnrealizedGainLossOnDerivatives" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Unrealized (gain) loss on interest rate swaps</link:label>
    <link:label id="lab_us-gaap_UnrealizedGainLossOnDerivatives_label_en-US" xlink:label="lab_us-gaap_UnrealizedGainLossOnDerivatives" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Unrealized Gain (Loss) on Derivatives</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnDerivatives" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_UnrealizedGainLossOnDerivatives"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_UnrealizedGainLossOnDerivatives" xlink:to="lab_us-gaap_UnrealizedGainLossOnDerivatives" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue_1c03ec76-c6f1-46e5-9870-103736afb158_terseLabel_en-US" xlink:label="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Cash and cash equivalents</link:label>
    <link:label id="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue_label_en-US" xlink:label="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash and Cash Equivalents, at Carrying Value</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_InterestPaidNet_262387f8-6d7f-4665-8122-7252bf6e8231_terseLabel_en-US" xlink:label="lab_us-gaap_InterestPaidNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Cash interest paid</link:label>
    <link:label id="lab_us-gaap_InterestPaidNet_label_en-US" xlink:label="lab_us-gaap_InterestPaidNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Interest Paid, Excluding Capitalized Interest, Operating Activities</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestPaidNet" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestPaidNet"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestPaidNet" xlink:to="lab_us-gaap_InterestPaidNet" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_cc915c16-09d9-40dd-be4b-65b53769952d_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Issued units (in shares)</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award, Shares Issued in Period</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_DebtInstrumentCovenantThresholdAxis_8b1815d8-52b1-4d49-bc65-496a77a683de_terseLabel_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantThresholdAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Threshold [Axis]</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantThresholdAxis_label_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantThresholdAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Threshold [Axis]</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantThresholdAxis_documentation_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantThresholdAxis" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Threshold</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_DebtInstrumentCovenantThresholdAxis" xlink:href="smlp-20240331.xsd#smlp_DebtInstrumentCovenantThresholdAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_DebtInstrumentCovenantThresholdAxis" xlink:to="lab_smlp_DebtInstrumentCovenantThresholdAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CreditFacilityDomain_3591dd70-ed2f-4b12-b25c-3e6182f0851e_terseLabel_en-US" xlink:label="lab_us-gaap_CreditFacilityDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Credit Facility</link:label>
    <link:label id="lab_us-gaap_CreditFacilityDomain_label_en-US" xlink:label="lab_us-gaap_CreditFacilityDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Credit Facility [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CreditFacilityDomain" xlink:to="lab_us-gaap_CreditFacilityDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_TemporaryEquitySharesIssued_10ba885b-3ef6-4643-b95a-90179b92de43_terseLabel_en-US" xlink:label="lab_us-gaap_TemporaryEquitySharesIssued" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Series A Preferred Units Issued (in shares)</link:label>
    <link:label id="lab_us-gaap_TemporaryEquitySharesIssued_label_en-US" xlink:label="lab_us-gaap_TemporaryEquitySharesIssued" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Temporary Equity, Shares Issued</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquitySharesIssued" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquitySharesIssued"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_TemporaryEquitySharesIssued" xlink:to="lab_us-gaap_TemporaryEquitySharesIssued" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_85cc13e5-2c83-486f-b011-11dbc89d3855_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Applicable margin (as a percent)</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Basis Spread on Variable Rate</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
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    <link:label id="lab_us-gaap_TypeOfCostGoodOrServiceExtensibleList_0ba15f4c-d953-428d-b9bd-931e4b1e5613_terseLabel_en-US" xlink:label="lab_us-gaap_TypeOfCostGoodOrServiceExtensibleList" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Type of Cost, Good or Service [Extensible List]</link:label>
    <link:label id="lab_us-gaap_TypeOfCostGoodOrServiceExtensibleList_label_en-US" xlink:label="lab_us-gaap_TypeOfCostGoodOrServiceExtensibleList" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cost, Product and Service [Extensible Enumeration]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfCostGoodOrServiceExtensibleList" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TypeOfCostGoodOrServiceExtensibleList"/>
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    <link:label id="lab_us-gaap_LongTermDebtNoncurrent_087252b2-0b79-463c-9595-836a1a9e6c62_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Long-term debt, net of issuance costs</link:label>
    <link:label id="lab_us-gaap_LongTermDebtNoncurrent_96db1b94-7440-4fc3-a844-30173c11ee92_verboseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtNoncurrent" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Total long-term debt</link:label>
    <link:label id="lab_us-gaap_LongTermDebtNoncurrent_label_en-US" xlink:label="lab_us-gaap_LongTermDebtNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-Term Debt, Excluding Current Maturities</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtNoncurrent" xlink:to="lab_us-gaap_LongTermDebtNoncurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ProceedsFromSaleOfEquityMethodInvestments_05da741a-250f-495e-8490-fec4940ed4d0_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromSaleOfEquityMethodInvestments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Proceeds from sale of equity method investment</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfEquityMethodInvestments" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromSaleOfEquityMethodInvestments"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromSaleOfEquityMethodInvestments" xlink:to="lab_us-gaap_ProceedsFromSaleOfEquityMethodInvestments" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_ContractWithCustomerLiabilityCurrentAdditions_d5cc66fe-90dd-4de0-b4f3-d8113a73952c_terseLabel_en-US" xlink:label="lab_smlp_ContractWithCustomerLiabilityCurrentAdditions" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Add: additions</link:label>
    <link:label id="lab_smlp_ContractWithCustomerLiabilityCurrentAdditions_label_en-US" xlink:label="lab_smlp_ContractWithCustomerLiabilityCurrentAdditions" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Contract With Customer Liability, Current, Additions</link:label>
    <link:label id="lab_smlp_ContractWithCustomerLiabilityCurrentAdditions_documentation_en-US" xlink:label="lab_smlp_ContractWithCustomerLiabilityCurrentAdditions" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Contract with customer liability current additions.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_ContractWithCustomerLiabilityCurrentAdditions" xlink:href="smlp-20240331.xsd#smlp_ContractWithCustomerLiabilityCurrentAdditions"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_ContractWithCustomerLiabilityCurrentAdditions" xlink:to="lab_smlp_ContractWithCustomerLiabilityCurrentAdditions" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_DamagesPayableToFederalGovernmentOverFiveYearsMember_67ab5f84-68cd-43be-b797-c7b80f443caf_terseLabel_en-US" xlink:label="lab_smlp_DamagesPayableToFederalGovernmentOverFiveYearsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Damages Payable To Federal Government over Five Years</link:label>
    <link:label id="lab_smlp_DamagesPayableToFederalGovernmentOverFiveYearsMember_label_en-US" xlink:label="lab_smlp_DamagesPayableToFederalGovernmentOverFiveYearsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Damages Payable To Federal Government over Five Years [Member]</link:label>
    <link:label id="lab_smlp_DamagesPayableToFederalGovernmentOverFiveYearsMember_documentation_en-US" xlink:label="lab_smlp_DamagesPayableToFederalGovernmentOverFiveYearsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Damages Payable To Federal Government over Five Years</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_DamagesPayableToFederalGovernmentOverFiveYearsMember" xlink:href="smlp-20240331.xsd#smlp_DamagesPayableToFederalGovernmentOverFiveYearsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_DamagesPayableToFederalGovernmentOverFiveYearsMember" xlink:to="lab_smlp_DamagesPayableToFederalGovernmentOverFiveYearsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_InterestRateContractMember_d7442df0-80ac-4f70-b5cd-7bccd81420d2_terseLabel_en-US" xlink:label="lab_us-gaap_InterestRateContractMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Interest Rate Contract</link:label>
    <link:label id="lab_us-gaap_InterestRateContractMember_label_en-US" xlink:label="lab_us-gaap_InterestRateContractMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Interest Rate Contract [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateContractMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestRateContractMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestRateContractMember" xlink:to="lab_us-gaap_InterestRateContractMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock_28f5ced5-2c36-43d1-9280-a8f07e9ce4c0_terseLabel_en-US" xlink:label="lab_us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Contract with Customer, Contract Asset, Contract Liability, and Receivable</link:label>
    <link:label id="lab_us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock" xlink:to="lab_us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RevenueFromContractWithCustomerTextBlock_77e79b1f-4201-49b1-8d54-da7f510ea3a6_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueFromContractWithCustomerTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">REVENUE</link:label>
    <link:label id="lab_us-gaap_RevenueFromContractWithCustomerTextBlock_label_en-US" xlink:label="lab_us-gaap_RevenueFromContractWithCustomerTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenue from Contract with Customer [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromContractWithCustomerTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenueFromContractWithCustomerTextBlock" xlink:to="lab_us-gaap_RevenueFromContractWithCustomerTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_9beebbde-635a-4a5d-80df-1f9ab4d81db5_negatedLabel_en-US" xlink:label="lab_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Capital expenditures</link:label>
    <link:label id="lab_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_label_en-US" xlink:label="lab_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Payments to Acquire Property, Plant, and Equipment</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:to="lab_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_CorporateAndOtherExpenses_eb18b66c-1aaf-410f-9378-0f3ac7df2b00_terseLabel_en-US" xlink:label="lab_smlp_CorporateAndOtherExpenses" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Corporate and Other expense</link:label>
    <link:label id="lab_smlp_CorporateAndOtherExpenses_label_en-US" xlink:label="lab_smlp_CorporateAndOtherExpenses" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Corporate And Other Expenses</link:label>
    <link:label id="lab_smlp_CorporateAndOtherExpenses_documentation_en-US" xlink:label="lab_smlp_CorporateAndOtherExpenses" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Corporate and other expenses.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_CorporateAndOtherExpenses" xlink:href="smlp-20240331.xsd#smlp_CorporateAndOtherExpenses"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_CorporateAndOtherExpenses" xlink:to="lab_smlp_CorporateAndOtherExpenses" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_GatheringServicesAndRelatedFeesMember_f3932f24-9220-441e-b361-3adb602cfa45_terseLabel_en-US" xlink:label="lab_smlp_GatheringServicesAndRelatedFeesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Gathering services and related fees</link:label>
    <link:label id="lab_smlp_GatheringServicesAndRelatedFeesMember_label_en-US" xlink:label="lab_smlp_GatheringServicesAndRelatedFeesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Gathering Services And Related Fees [Member]</link:label>
    <link:label id="lab_smlp_GatheringServicesAndRelatedFeesMember_documentation_en-US" xlink:label="lab_smlp_GatheringServicesAndRelatedFeesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Gathering services and related fees.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_GatheringServicesAndRelatedFeesMember" xlink:href="smlp-20240331.xsd#smlp_GatheringServicesAndRelatedFeesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_GatheringServicesAndRelatedFeesMember" xlink:to="lab_smlp_GatheringServicesAndRelatedFeesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_ContractWithCustomerLiabilityCurrentRevenueRecognized_b397e363-9ad5-486d-807f-01a525921422_negatedLabel_en-US" xlink:label="lab_smlp_ContractWithCustomerLiabilityCurrentRevenueRecognized" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Less: revenue recognized and other</link:label>
    <link:label id="lab_smlp_ContractWithCustomerLiabilityCurrentRevenueRecognized_label_en-US" xlink:label="lab_smlp_ContractWithCustomerLiabilityCurrentRevenueRecognized" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Contract With Customer Liability, Current, Revenue Recognized</link:label>
    <link:label id="lab_smlp_ContractWithCustomerLiabilityCurrentRevenueRecognized_documentation_en-US" xlink:label="lab_smlp_ContractWithCustomerLiabilityCurrentRevenueRecognized" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Contract with customer liability current revenue recognized.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_ContractWithCustomerLiabilityCurrentRevenueRecognized" xlink:href="smlp-20240331.xsd#smlp_ContractWithCustomerLiabilityCurrentRevenueRecognized"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_ContractWithCustomerLiabilityCurrentRevenueRecognized" xlink:to="lab_smlp_ContractWithCustomerLiabilityCurrentRevenueRecognized" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_Assets_18c286e4-dc49-4bcd-ae92-cf7144de91fa_totalLabel_en-US" xlink:label="lab_us-gaap_Assets" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">TOTAL ASSETS</link:label>
    <link:label id="lab_us-gaap_Assets_1fd50409-2808-4a31-87d7-808fdd857265_terseLabel_en-US" xlink:label="lab_us-gaap_Assets" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Assets</link:label>
    <link:label id="lab_us-gaap_Assets_label_en-US" xlink:label="lab_us-gaap_Assets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Assets</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Assets"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_Assets" xlink:to="lab_us-gaap_Assets" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodThree_68eeff7c-85b2-4a2b-8ef1-453f659e1aab_terseLabel_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodThree" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt instrument, covenant, excess cash flow offer to purchase, basis point increase, period three</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodThree_label_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodThree" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Excess Cash Flow Offer To Purchase, Basis Point Increase, Period Three</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodThree_documentation_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodThree" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Excess Cash Flow Offer To Purchase, Basis Point Increase, Period Three</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodThree" xlink:href="smlp-20240331.xsd#smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodThree"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodThree" xlink:to="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodThree" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncomeLossFromEquityMethodInvestments_3c7fab34-1fbe-4bd9-af99-14497498eb57_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeLossFromEquityMethodInvestments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Income from equity method investees</link:label>
    <link:label id="lab_us-gaap_IncomeLossFromEquityMethodInvestments_41160310-34a1-4aae-a0c5-b92e862de7a1_negatedLabel_en-US" xlink:label="lab_us-gaap_IncomeLossFromEquityMethodInvestments" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Income from equity method investees</link:label>
    <link:label id="lab_us-gaap_IncomeLossFromEquityMethodInvestments_label_en-US" xlink:label="lab_us-gaap_IncomeLossFromEquityMethodInvestments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Income (Loss) from Equity Method Investments</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeLossFromEquityMethodInvestments"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeLossFromEquityMethodInvestments" xlink:to="lab_us-gaap_IncomeLossFromEquityMethodInvestments" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LossContingenciesLineItems_cefd9b03-630c-4ceb-bf9f-0cd2d490d48f_terseLabel_en-US" xlink:label="lab_us-gaap_LossContingenciesLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Loss Contingencies [Line Items]</link:label>
    <link:label id="lab_us-gaap_LossContingenciesLineItems_label_en-US" xlink:label="lab_us-gaap_LossContingenciesLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Loss Contingencies [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LossContingenciesLineItems" xlink:to="lab_us-gaap_LossContingenciesLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_CoverAbstract_158f429c-6a02-455d-8c78-14d9b9255633_terseLabel_en-US" xlink:label="lab_dei_CoverAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Cover [Abstract]</link:label>
    <link:label id="lab_dei_CoverAbstract_label_en-US" xlink:label="lab_dei_CoverAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cover [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CoverAbstract" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_CoverAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_CoverAbstract" xlink:to="lab_dei_CoverAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodOne_f10a1142-a492-4b7a-8c88-d0969beaf89a_terseLabel_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodOne" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt instrument, covenant, excess cash flow offer to purchase, basis point increase, period one</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodOne_label_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodOne" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Excess Cash Flow Offer To Purchase, Basis Point Increase, Period One</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodOne_documentation_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodOne" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Excess Cash Flow Offer To Purchase, Basis Point Increase, Period One</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodOne" xlink:href="smlp-20240331.xsd#smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodOne"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodOne" xlink:to="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodOne" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_SummitUticaMember_bea3ed01-e9f3-4010-82f5-b1c49356dc0e_terseLabel_en-US" xlink:label="lab_smlp_SummitUticaMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Summit Utica</link:label>
    <link:label id="lab_smlp_SummitUticaMember_label_en-US" xlink:label="lab_smlp_SummitUticaMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Summit Utica [Member]</link:label>
    <link:label id="lab_smlp_SummitUticaMember_documentation_en-US" xlink:label="lab_smlp_SummitUticaMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Summit Utica</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_SummitUticaMember" xlink:href="smlp-20240331.xsd#smlp_SummitUticaMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_SummitUticaMember" xlink:to="lab_smlp_SummitUticaMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SubsequentEventsTextBlock_59c57a38-f211-44f9-9c99-85b725dd7c1a_terseLabel_en-US" xlink:label="lab_us-gaap_SubsequentEventsTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">SUBSEQUENT EVENTS</link:label>
    <link:label id="lab_us-gaap_SubsequentEventsTextBlock_label_en-US" xlink:label="lab_us-gaap_SubsequentEventsTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Subsequent Events [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventsTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsequentEventsTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventsTextBlock" xlink:to="lab_us-gaap_SubsequentEventsTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AmortizationOfFinancingCosts_ae5c39f5-2282-4de3-abde-b70675ab9aab_terseLabel_en-US" xlink:label="lab_us-gaap_AmortizationOfFinancingCosts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Amortization of debt issuance costs</link:label>
    <link:label id="lab_us-gaap_AmortizationOfFinancingCosts_label_en-US" xlink:label="lab_us-gaap_AmortizationOfFinancingCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Amortization of Debt Issuance Costs</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AmortizationOfFinancingCosts"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AmortizationOfFinancingCosts" xlink:to="lab_us-gaap_AmortizationOfFinancingCosts" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_DebtInstrumentIssuedAsAPercentageOfFaceValue_6240bcda-f21b-463e-9488-d0e654883356_terseLabel_en-US" xlink:label="lab_smlp_DebtInstrumentIssuedAsAPercentageOfFaceValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt issued as a percent of face value</link:label>
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    <link:label id="lab_smlp_DebtInstrumentIssuedAsAPercentageOfFaceValue_documentation_en-US" xlink:label="lab_smlp_DebtInstrumentIssuedAsAPercentageOfFaceValue" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Debt Instrument, Issued As A Percentage of Face Value</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_DebtInstrumentIssuedAsAPercentageOfFaceValue" xlink:href="smlp-20240331.xsd#smlp_DebtInstrumentIssuedAsAPercentageOfFaceValue"/>
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    <link:label id="lab_smlp_NoncontrollingInterestInSubsidiaryNetIncomeLossPreferredUnitHolders_5f783220-aaef-409e-95fc-c0862726de5f_negatedTerseLabel_en-US" xlink:label="lab_smlp_NoncontrollingInterestInSubsidiaryNetIncomeLossPreferredUnitHolders" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Less: Net income attributable to Subsidiary Series A Preferred Units</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_smlp_NoncontrollingInterestInSubsidiaryNetIncomeLossPreferredUnitHolders" xlink:href="smlp-20240331.xsd#smlp_NoncontrollingInterestInSubsidiaryNetIncomeLossPreferredUnitHolders"/>
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    <link:label id="lab_us-gaap_InterestCostsIncurredCapitalized_f3555953-80e2-4602-8dc5-33cecac8c554_terseLabel_en-US" xlink:label="lab_us-gaap_InterestCostsIncurredCapitalized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Capitalized interest</link:label>
    <link:label id="lab_us-gaap_InterestCostsIncurredCapitalized_label_en-US" xlink:label="lab_us-gaap_InterestCostsIncurredCapitalized" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Capitalized Interest Costs, Including Allowance for Funds Used During Construction</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestCostsIncurredCapitalized" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestCostsIncurredCapitalized"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestCostsIncurredCapitalized" xlink:to="lab_us-gaap_InterestCostsIncurredCapitalized" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_WeightedAverageLimitedPartnershipUnitsOutstanding_3b20d41c-404b-4e7d-9817-6b5dea9b90e9_terseLabel_en-US" xlink:label="lab_us-gaap_WeightedAverageLimitedPartnershipUnitsOutstanding" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Common units - basic (in shares)</link:label>
    <link:label id="lab_us-gaap_WeightedAverageLimitedPartnershipUnitsOutstanding_label_en-US" xlink:label="lab_us-gaap_WeightedAverageLimitedPartnershipUnitsOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Weighted Average Limited Partnership Units Outstanding, Basic</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageLimitedPartnershipUnitsOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageLimitedPartnershipUnitsOutstanding"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_WeightedAverageLimitedPartnershipUnitsOutstanding" xlink:to="lab_us-gaap_WeightedAverageLimitedPartnershipUnitsOutstanding" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodTwo_8e7bdfce-ccd8-4071-a57f-1093596ee625_terseLabel_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodTwo" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt instrument, covenant, excess cash flow offer to purchase, basis point increase, period two</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodTwo_label_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodTwo" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Excess Cash Flow Offer To Purchase, Basis Point Increase, Period Two</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodTwo_documentation_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodTwo" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Excess Cash Flow Offer To Purchase, Basis Point Increase, Period Two</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodTwo" xlink:href="smlp-20240331.xsd#smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodTwo"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodTwo" xlink:to="lab_smlp_DebtInstrumentCovenantExcessCashFlowOfferToPurchaseBasisPointIncreasePeriodTwo" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PreferredUnitsOutstanding_af3cbec7-d0b2-41fe-89c8-0186e17a56d7_verboseLabel_en-US" xlink:label="lab_us-gaap_PreferredUnitsOutstanding" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Preferred units, outstanding (in shares)</link:label>
    <link:label id="lab_us-gaap_PreferredUnitsOutstanding_77faa6a8-51dc-4919-8df1-97b3e1868fe2_terseLabel_en-US" xlink:label="lab_us-gaap_PreferredUnitsOutstanding" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Subsidiary Series A preferred unitholders, outstanding (in shares)</link:label>
    <link:label id="lab_us-gaap_PreferredUnitsOutstanding_label_en-US" xlink:label="lab_us-gaap_PreferredUnitsOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Preferred Units, Outstanding</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredUnitsOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredUnitsOutstanding"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredUnitsOutstanding" xlink:to="lab_us-gaap_PreferredUnitsOutstanding" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SeriesAPreferredStockMember_74d271c4-0dfd-4b30-9d49-1cf35c658c85_terseLabel_en-US" xlink:label="lab_us-gaap_SeriesAPreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Series A Preferred Units</link:label>
    <link:label id="lab_us-gaap_SeriesAPreferredStockMember_e328068a-d3d3-46be-b87d-edd08c9af164_verboseLabel_en-US" xlink:label="lab_us-gaap_SeriesAPreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Series A Preferred Units</link:label>
    <link:label id="lab_us-gaap_SeriesAPreferredStockMember_label_en-US" xlink:label="lab_us-gaap_SeriesAPreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Series A Preferred Stock [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesAPreferredStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SeriesAPreferredStockMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SeriesAPreferredStockMember" xlink:to="lab_us-gaap_SeriesAPreferredStockMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtInstrumentInterestRateDuringPeriod_dba6aca8-c74e-40b5-a698-c69275961558_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentInterestRateDuringPeriod" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt instrument, interest rate</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentInterestRateDuringPeriod_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentInterestRateDuringPeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Interest Rate During Period</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateDuringPeriod" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentInterestRateDuringPeriod"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentInterestRateDuringPeriod" xlink:to="lab_us-gaap_DebtInstrumentInterestRateDuringPeriod" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherLiabilitiesNoncurrent_206b2701-4c86-4bdb-8d36-b20cd579e392_terseLabel_en-US" xlink:label="lab_us-gaap_OtherLiabilitiesNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other noncurrent liabilities</link:label>
    <link:label id="lab_us-gaap_OtherLiabilitiesNoncurrent_label_en-US" xlink:label="lab_us-gaap_OtherLiabilitiesNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Liabilities, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherLiabilitiesNoncurrent" xlink:to="lab_us-gaap_OtherLiabilitiesNoncurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ScheduleOfCashFlowSupplementalDisclosuresTableTextBlock_a52e00bd-042b-4129-9b79-324051148983_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfCashFlowSupplementalDisclosuresTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Cash Flow, Supplemental Disclosures</link:label>
    <link:label id="lab_us-gaap_ScheduleOfCashFlowSupplementalDisclosuresTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfCashFlowSupplementalDisclosuresTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfCashFlowSupplementalDisclosuresTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfCashFlowSupplementalDisclosuresTableTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfCashFlowSupplementalDisclosuresTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfCashFlowSupplementalDisclosuresTableTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RevenueRemainingPerformanceObligation_4904dd6b-2916-4771-a00a-a95cf356386d_verboseLabel_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligation" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Revenue, remaining performance obligation, amount</link:label>
    <link:label id="lab_us-gaap_RevenueRemainingPerformanceObligation_label_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenue, Remaining Performance Obligation, Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligation" xlink:to="lab_us-gaap_RevenueRemainingPerformanceObligation" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ConstructionInProgressMember_43f73e72-07ae-487c-a4ba-90017b8dbf96_terseLabel_en-US" xlink:label="lab_us-gaap_ConstructionInProgressMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Construction in progress</link:label>
    <link:label id="lab_us-gaap_ConstructionInProgressMember_label_en-US" xlink:label="lab_us-gaap_ConstructionInProgressMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Construction in Progress [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionInProgressMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConstructionInProgressMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConstructionInProgressMember" xlink:to="lab_us-gaap_ConstructionInProgressMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SegmentReportingDisclosureTextBlock_ea01270d-6c4b-4008-9e8c-e844f72b52cc_terseLabel_en-US" xlink:label="lab_us-gaap_SegmentReportingDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">SEGMENT INFORMATION</link:label>
    <link:label id="lab_us-gaap_SegmentReportingDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_SegmentReportingDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Segment Reporting Disclosure [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentReportingDisclosureTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SegmentReportingDisclosureTextBlock" xlink:to="lab_us-gaap_SegmentReportingDisclosureTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LimitedPartnersCapitalAccountUnitsIssued_8cb34407-21c4-459d-a0b3-6f9e3cf983e7_terseLabel_en-US" xlink:label="lab_us-gaap_LimitedPartnersCapitalAccountUnitsIssued" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Common limited partner capital, issued (in shares)</link:label>
    <link:label id="lab_us-gaap_LimitedPartnersCapitalAccountUnitsIssued_label_en-US" xlink:label="lab_us-gaap_LimitedPartnersCapitalAccountUnitsIssued" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Limited Partners' Capital Account, Units Issued</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LimitedPartnersCapitalAccountUnitsIssued" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LimitedPartnersCapitalAccountUnitsIssued"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LimitedPartnersCapitalAccountUnitsIssued" xlink:to="lab_us-gaap_LimitedPartnersCapitalAccountUnitsIssued" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_537f6bea-cf31-44ea-b27c-a552315981b6_totalLabel_en-US" xlink:label="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net change in cash, cash equivalents and restricted cash</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
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    <link:label id="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_182e66ee-454b-47e2-bdcc-d0039a0991d0_terseLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Cash flows from financing activities:</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_ac3007b4-2a68-47e6-bdc8-28a060be9218_totalLabel_en-US" xlink:label="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Income (loss) before income taxes and equity method investment income</link:label>
    <link:label id="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_27b2ee2d-34dd-4309-8cd6-bf2368afb2b2_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Income (loss) before income taxes and equity method investment income</link:label>
    <link:label id="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_label_en-US" xlink:label="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:to="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SecuredDebtMember_4fa2af6b-a15b-4359-be8a-1cf7b0d0f5b7_terseLabel_en-US" xlink:label="lab_us-gaap_SecuredDebtMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Secured Debt</link:label>
    <link:label id="lab_us-gaap_SecuredDebtMember_label_en-US" xlink:label="lab_us-gaap_SecuredDebtMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Secured Debt [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SecuredDebtMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SecuredDebtMember" xlink:to="lab_us-gaap_SecuredDebtMember" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_DebtInstrumentCovenantBelowCashThresholdMember_ab2ec025-444e-4774-9c29-dc96ec4dda0c_terseLabel_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantBelowCashThresholdMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Less than cash threshold</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantBelowCashThresholdMember_label_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantBelowCashThresholdMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Below Cash Threshold [Member]</link:label>
    <link:label id="lab_smlp_DebtInstrumentCovenantBelowCashThresholdMember_documentation_en-US" xlink:label="lab_smlp_DebtInstrumentCovenantBelowCashThresholdMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Debt Instrument, Covenant, Below Cash Threshold</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_DebtInstrumentCovenantBelowCashThresholdMember" xlink:href="smlp-20240331.xsd#smlp_DebtInstrumentCovenantBelowCashThresholdMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_DebtInstrumentCovenantBelowCashThresholdMember" xlink:to="lab_smlp_DebtInstrumentCovenantBelowCashThresholdMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtInstrumentLineItems_7279d071-1d39-4b99-bde1-4622d3766e74_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt Instrument [Line Items]</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentLineItems_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentLineItems" xlink:to="lab_us-gaap_DebtInstrumentLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_EntityCurrentReportingStatus_692bd49d-b61c-4578-a742-2b9a3425927e_terseLabel_en-US" xlink:label="lab_dei_EntityCurrentReportingStatus" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Entity Current Reporting Status</link:label>
    <link:label id="lab_dei_EntityCurrentReportingStatus_label_en-US" xlink:label="lab_dei_EntityCurrentReportingStatus" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Current Reporting Status</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCurrentReportingStatus" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCurrentReportingStatus"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityCurrentReportingStatus" xlink:to="lab_dei_EntityCurrentReportingStatus" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PreferredStockRedemptionAmount_4b7502b6-102a-4db5-9d33-6c282abbf6c6_terseLabel_en-US" xlink:label="lab_us-gaap_PreferredStockRedemptionAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Redemption amount</link:label>
    <link:label id="lab_us-gaap_PreferredStockRedemptionAmount_label_en-US" xlink:label="lab_us-gaap_PreferredStockRedemptionAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Preferred Stock, Redemption Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockRedemptionAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockRedemptionAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredStockRedemptionAmount" xlink:to="lab_us-gaap_PreferredStockRedemptionAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PartnersCapitalAccountUnits_7b59f226-92b6-45f0-b1fc-240f062ebd1c_periodStartLabel_en-US" xlink:label="lab_us-gaap_PartnersCapitalAccountUnits" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Units, beginning balance (in shares)</link:label>
    <link:label id="lab_us-gaap_PartnersCapitalAccountUnits_66426a4b-30d3-4b59-a2ca-094a039a1ed1_periodEndLabel_en-US" xlink:label="lab_us-gaap_PartnersCapitalAccountUnits" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Units, ending balance (in shares)</link:label>
    <link:label id="lab_us-gaap_PartnersCapitalAccountUnits_label_en-US" xlink:label="lab_us-gaap_PartnersCapitalAccountUnits" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Partners' Capital Account, Units</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PartnersCapitalAccountUnits" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PartnersCapitalAccountUnits"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PartnersCapitalAccountUnits" xlink:to="lab_us-gaap_PartnersCapitalAccountUnits" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtInstrumentRedemptionPeriodTwoMember_ec32a1d2-f2f2-4d8e-8aad-96fc13dd3aa4_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentRedemptionPeriodTwoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Beginning October 15, 2024</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentRedemptionPeriodTwoMember_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentRedemptionPeriodTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Redemption, Period Two [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodTwoMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentRedemptionPeriodTwoMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodTwoMember" xlink:to="lab_us-gaap_DebtInstrumentRedemptionPeriodTwoMember" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_WorkingCapitalCreditFacilityMember_b1aeedfa-89d3-4fd9-86f8-8d772c2dc92c_terseLabel_en-US" xlink:label="lab_smlp_WorkingCapitalCreditFacilityMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Working Capital Credit Facility</link:label>
    <link:label id="lab_smlp_WorkingCapitalCreditFacilityMember_label_en-US" xlink:label="lab_smlp_WorkingCapitalCreditFacilityMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Working Capital Credit Facility [Member]</link:label>
    <link:label id="lab_smlp_WorkingCapitalCreditFacilityMember_documentation_en-US" xlink:label="lab_smlp_WorkingCapitalCreditFacilityMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Working Capital Credit Facility.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_WorkingCapitalCreditFacilityMember" xlink:href="smlp-20240331.xsd#smlp_WorkingCapitalCreditFacilityMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_WorkingCapitalCreditFacilityMember" xlink:to="lab_smlp_WorkingCapitalCreditFacilityMember" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_NumberOfDirectors_06f39202-5901-44fd-a2a3-224ba5cfb02a_terseLabel_en-US" xlink:label="lab_smlp_NumberOfDirectors" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of directors</link:label>
    <link:label id="lab_smlp_NumberOfDirectors_label_en-US" xlink:label="lab_smlp_NumberOfDirectors" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Number Of Directors</link:label>
    <link:label id="lab_smlp_NumberOfDirectors_documentation_en-US" xlink:label="lab_smlp_NumberOfDirectors" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Number of directors.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_NumberOfDirectors" xlink:href="smlp-20240331.xsd#smlp_NumberOfDirectors"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_NumberOfDirectors" xlink:to="lab_smlp_NumberOfDirectors" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RevenuesAbstract_cfa0aea9-64a6-4265-a058-91112854fdae_terseLabel_en-US" xlink:label="lab_us-gaap_RevenuesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Revenues:</link:label>
    <link:label id="lab_us-gaap_RevenuesAbstract_label_en-US" xlink:label="lab_us-gaap_RevenuesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenues [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenuesAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenuesAbstract" xlink:to="lab_us-gaap_RevenuesAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed_a33abb44-19f9-489e-a82b-ba84c018402b_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Redemption percentage (as a percent)</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed" xlink:to="lab_us-gaap_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_ContractWithCustomerLiabilityNoncurrentReclassificationToCurrent_836bbe6e-192c-468b-930a-d97508132af1_negatedLabel_en-US" xlink:label="lab_smlp_ContractWithCustomerLiabilityNoncurrentReclassificationToCurrent" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Less: reclassification to current deferred revenue and other</link:label>
    <link:label id="lab_smlp_ContractWithCustomerLiabilityNoncurrentReclassificationToCurrent_label_en-US" xlink:label="lab_smlp_ContractWithCustomerLiabilityNoncurrentReclassificationToCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Contract With Customer Liability, Noncurrent, Reclassification To Current</link:label>
    <link:label id="lab_smlp_ContractWithCustomerLiabilityNoncurrentReclassificationToCurrent_documentation_en-US" xlink:label="lab_smlp_ContractWithCustomerLiabilityNoncurrentReclassificationToCurrent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Contract with customer liability noncurrent reclassification to current.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_ContractWithCustomerLiabilityNoncurrentReclassificationToCurrent" xlink:href="smlp-20240331.xsd#smlp_ContractWithCustomerLiabilityNoncurrentReclassificationToCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_ContractWithCustomerLiabilityNoncurrentReclassificationToCurrent" xlink:to="lab_smlp_ContractWithCustomerLiabilityNoncurrentReclassificationToCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_smlp_NaturalResourceDamagesToFederalAndStateGovernmentsMember_3e743ffd-4396-42f7-ad00-3ae958192273_terseLabel_en-US" xlink:label="lab_smlp_NaturalResourceDamagesToFederalAndStateGovernmentsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Natural Resource Damages To Federal and State Governments</link:label>
    <link:label id="lab_smlp_NaturalResourceDamagesToFederalAndStateGovernmentsMember_label_en-US" xlink:label="lab_smlp_NaturalResourceDamagesToFederalAndStateGovernmentsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Natural Resource Damages To Federal and State Governments [Member]</link:label>
    <link:label id="lab_smlp_NaturalResourceDamagesToFederalAndStateGovernmentsMember_documentation_en-US" xlink:label="lab_smlp_NaturalResourceDamagesToFederalAndStateGovernmentsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Natural Resource Damages To Federal and State Governments</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_smlp_NaturalResourceDamagesToFederalAndStateGovernmentsMember" xlink:href="smlp-20240331.xsd#smlp_NaturalResourceDamagesToFederalAndStateGovernmentsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_smlp_NaturalResourceDamagesToFederalAndStateGovernmentsMember" xlink:to="lab_smlp_NaturalResourceDamagesToFederalAndStateGovernmentsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StatementBusinessSegmentsAxis_c148c575-c36e-47f6-834e-58f6b1dde55e_terseLabel_en-US" xlink:label="lab_us-gaap_StatementBusinessSegmentsAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Segments</link:label>
    <link:label id="lab_us-gaap_StatementBusinessSegmentsAxis_label_en-US" xlink:label="lab_us-gaap_StatementBusinessSegmentsAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Segments [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis" xlink:to="lab_us-gaap_StatementBusinessSegmentsAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StatementLineItems_a806397b-71ee-4285-af91-d99e736c0d4c_terseLabel_en-US" xlink:label="lab_us-gaap_StatementLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Statement [Line Items]</link:label>
    <link:label id="lab_us-gaap_StatementLineItems_label_en-US" xlink:label="lab_us-gaap_StatementLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statement [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementLineItems" xlink:to="lab_us-gaap_StatementLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ConcentrationRiskTable_2dd8b58f-382b-425b-b79c-dd12d34577fe_terseLabel_en-US" xlink:label="lab_us-gaap_ConcentrationRiskTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Concentration Risk [Table]</link:label>
    <link:label id="lab_us-gaap_ConcentrationRiskTable_label_en-US" xlink:label="lab_us-gaap_ConcentrationRiskTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Concentration Risk [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConcentrationRiskTable" xlink:to="lab_us-gaap_ConcentrationRiskTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EstimateOfFairValueFairValueDisclosureMember_3e5ae9a7-679c-43ac-9a89-e1b18576b132_terseLabel_en-US" xlink:label="lab_us-gaap_EstimateOfFairValueFairValueDisclosureMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value</link:label>
    <link:label id="lab_us-gaap_EstimateOfFairValueFairValueDisclosureMember_label_en-US" xlink:label="lab_us-gaap_EstimateOfFairValueFairValueDisclosureMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Estimate of Fair Value Measurement [Member]</link:label>
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