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  <xs:element id="pagp_LimitedLiabilityCompanyLLCorLimitedPartnershipLPMembersorLimitedPartnersOwnershipInterestUnits" abstract="false" name="LimitedLiabilityCompanyLLCorLimitedPartnershipLPMembersorLimitedPartnersOwnershipInterestUnits" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="pagp_IndictmentNumberofMisdemeanorChargesGuiltyVerdict" abstract="false" name="IndictmentNumberofMisdemeanorChargesGuiltyVerdict" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="pagp_AgreementToStoreAndTransportCrudeOilOnPipelineOfEquityMethodInvesteeMember" abstract="true" name="AgreementToStoreAndTransportCrudeOilOnPipelineOfEquityMethodInvesteeMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_ContractWithCustomerAssetAndLiabilityTable" abstract="true" name="ContractWithCustomerAssetAndLiabilityTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="pagp_InventoryWriteDownNoncurrent" abstract="false" name="InventoryWriteDownNoncurrent" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_PlainsAapLPMember" abstract="true" name="PlainsAapLPMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_NetShortTimeSpreadPositionOnAnticipatedCrudeOilLeaseGatheringPurchaseContractsMember" abstract="true" name="NetShortTimeSpreadPositionOnAnticipatedCrudeOilLeaseGatheringPurchaseContractsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_ConsentDecreeCompensationForInjuriesToDestructionOfLossOfLossOfUseOfNaturalResourcesMember" abstract="true" name="ConsentDecreeCompensationForInjuriesToDestructionOfLossOfLossOfUseOfNaturalResourcesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_LongTermInventoryCostingAdjustments" abstract="false" name="LongTermInventoryCostingAdjustments" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_SegmentTransportationMember" abstract="true" name="SegmentTransportationMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_SaddlehornPipelineCompanyLlcMember" abstract="true" name="SaddlehornPipelineCompanyLlcMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_ScheduleOfInventoryLinefillAndBaseGasAndLongTermInventoryTableTextBlock" abstract="false" name="ScheduleOfInventoryLinefillAndBaseGasAndLongTermInventoryTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType"/>
  <xs:element id="pagp_MaintenanceCapital" abstract="false" name="MaintenanceCapital" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_RedRiverPipelineCompanyLLCMember" abstract="true" name="RedRiverPipelineCompanyLLCMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_LineOfCreditAndCommercialPaperMember" abstract="true" name="LineOfCreditAndCommercialPaperMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_InitialMargin" abstract="false" name="InitialMargin" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_LimitedPartnersCapitalSharesIssuedFromConversion" abstract="false" name="LimitedPartnersCapitalSharesIssuedFromConversion" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="pagp_OtherEquityMethodInvestmentsMember" abstract="true" name="OtherEquityMethodInvestmentsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_CrudeOilTransactionsMember" abstract="true" name="CrudeOilTransactionsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_DeficienciesUnderMinimumVolumeCommitmentsNet" abstract="false" name="DeficienciesUnderMinimumVolumeCommitmentsNet" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_CactusIIPipelineLLCMember" abstract="true" name="CactusIIPipelineLLCMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_NetLongPositionOnCrudeOilDerivativeContractsMember" abstract="true" name="NetLongPositionOnCrudeOilDerivativeContractsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_OffsettingAssetsLiabilitiesTable" abstract="true" name="OffsettingAssetsLiabilitiesTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="pagp_PlainsAllAmericanPipelineLPMember" abstract="true" name="PlainsAllAmericanPipelineLPMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_OtherDebtMember" abstract="true" name="OtherDebtMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_CapitalContributionsToEquityMethodInvestees" abstract="false" name="CapitalContributionsToEquityMethodInvestees" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_TradeAccountsReceivableAndOtherReceivablesNetMember" abstract="true" name="TradeAccountsReceivableAndOtherReceivablesNetMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_TariffActivitiesMember" abstract="true" name="TariffActivitiesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_LinefillAndBaseGas" abstract="false" name="LinefillAndBaseGas" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_EagleFordTerminalsCorpusChristiLlcMember" abstract="true" name="EagleFordTerminalsCorpusChristiLlcMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_LosAngelesBasinCrudeOilTerminalsMember" abstract="true" name="LosAngelesBasinCrudeOilTerminalsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_IndictmentInCaliforniaSuperiorCourtSantaBarbaraCountyMember" abstract="true" name="IndictmentInCaliforniaSuperiorCourtSantaBarbaraCountyMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_SegmentSupplyAndLogisticsMember" abstract="true" name="SegmentSupplyAndLogisticsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_SegmentAdjustedEBITDA" abstract="false" name="SegmentAdjustedEBITDA" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_IndictmentTotalNumberofCountsJuryDeadlocked" abstract="false" name="IndictmentTotalNumberofCountsJuryDeadlocked" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="pagp_EightForwardStartingThirtyYearInterestRateSwaps3.06PercentMember" abstract="true" name="EightForwardStartingThirtyYearInterestRateSwaps3.06PercentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationDerivativesEnteredInto" abstract="false" name="FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationDerivativesEnteredInto" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_OrganizationConsolidationAndPresentationOfFinancialStatementsTable" abstract="true" name="OrganizationConsolidationAndPresentationOfFinancialStatementsTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="pagp_TariffActivitiesCrudeOilPipelinesMember" abstract="true" name="TariffActivitiesCrudeOilPipelinesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_SharesClassAMember" abstract="true" name="SharesClassAMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_VariationMarginPostedReturned" abstract="false" name="VariationMarginPostedReturned" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_IndictmentNumberofMisdemeanorChargesNotGuiltyVerdictStrictLiabilityAnimalTakingsCount" abstract="false" name="IndictmentNumberofMisdemeanorChargesNotGuiltyVerdictStrictLiabilityAnimalTakingsCount" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="pagp_CounterpartyDeficiencies" abstract="false" name="CounterpartyDeficiencies" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_ChangeInContractWithCustomerLiabilityRollForward" abstract="true" name="ChangeInContractWithCustomerLiabilityRollForward" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="pagp_PublicUnitHoldersMember" abstract="true" name="PublicUnitHoldersMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_SeriesaPreferredUnitsMember" abstract="true" name="SeriesaPreferredUnitsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_InventoryWeightedAveragePricePerUnitLinefillandBaseGas1" abstract="false" name="InventoryWeightedAveragePricePerUnitLinefillandBaseGas1" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="srt-types:perUnitItemType"/>
  <xs:element id="pagp_FieldOperatingCostsMember" abstract="true" name="FieldOperatingCostsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_LossContingencyNumberOfCasesConsolidatedIntoSingleProceeding" abstract="false" name="LossContingencyNumberOfCasesConsolidatedIntoSingleProceeding" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="pagp_CommonUnitsMember" abstract="true" name="CommonUnitsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_SharesClassCMember" abstract="true" name="SharesClassCMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_OrganizationAndBasisOfPresentationLineItems" abstract="true" name="OrganizationAndBasisOfPresentationLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="pagp_AAPManagementUnitsMember" abstract="true" name="AAPManagementUnitsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_IndictmentTotalNumberofCountsJuryDeadlockedStrictLiabilityAnimalTakingsCount" abstract="false" name="IndictmentTotalNumberofCountsJuryDeadlockedStrictLiabilityAnimalTakingsCount" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="pagp_NetProceedsFromRepaymentsOfHedgedInventoryFacility" abstract="false" name="NetProceedsFromRepaymentsOfHedgedInventoryFacility" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_IndictmentNumberofMisdemeanorChargesGuiltyVerdictStrictLiabilityAnimalTakingsCount" abstract="false" name="IndictmentNumberofMisdemeanorChargesGuiltyVerdictStrictLiabilityAnimalTakingsCount" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="pagp_EightForwardStartingThirtyYearInterestRateSwaps138PercentMember" abstract="true" name="EightForwardStartingThirtyYearInterestRateSwaps138PercentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_IndictmentTotalNumberOfCounts" abstract="false" name="IndictmentTotalNumberOfCounts" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="pagp_ForeignExchangeForwardContractsThatExchangeCanadianDollarsForUSDollarsAtAverageRateDisclosedMaturingIn2020Member" abstract="true" name="ForeignExchangeForwardContractsThatExchangeCanadianDollarsForUSDollarsAtAverageRateDisclosedMaturingIn2020Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_ClassActionLawsuitsMember" abstract="true" name="ClassActionLawsuitsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_ContractWithCustomerContractualRightsOfOffsetWithCounterparties" abstract="false" name="ContractWithCustomerContractualRightsOfOffsetWithCounterparties" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_OtherInventoryMember" abstract="true" name="OtherInventoryMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_STACKPipelineLLCMember" abstract="true" name="STACKPipelineLLCMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_RailLoadAndUnloadMember" abstract="true" name="RailLoadAndUnloadMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_AAPUnitsMember" abstract="true" name="AAPUnitsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_CrudeOilGradeBasisPositionMember" abstract="true" name="CrudeOilGradeBasisPositionMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_GainLossOnSaleOfAssetsAndAssetImpairmentChargesMember" abstract="true" name="GainLossOnSaleOfAssetsAndAssetImpairmentChargesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_ConsentDecreeCivilPenaltiesMember" abstract="true" name="ConsentDecreeCivilPenaltiesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_GainLossAndImpairmentOnInvestmentInUnconsolidatedEntitiesNet" abstract="false" name="GainLossAndImpairmentOnInvestmentInUnconsolidatedEntitiesNet" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_IntangibleAssetsEstimateOfRiskTheoreticalMarketParticipant" abstract="false" name="IntangibleAssetsEstimateOfRiskTheoreticalMarketParticipant" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="num:percentItemType"/>
  <xs:element id="pagp_ShortWTIPositionContractsRelatedToSubsequentSaleOfProductMember" abstract="true" name="ShortWTIPositionContractsRelatedToSubsequentSaleOfProductMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_EstimatedSizeOfRelease" abstract="false" name="EstimatedSizeOfRelease" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="num:volumeItemType"/>
  <xs:element id="pagp_InventoryLinefillAndBaseGasAndLongTermInventoryDisclosureAbstract" abstract="true" name="InventoryLinefillAndBaseGasAndLongTermInventoryDisclosureAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="pagp_MinimumVolumeCommitmentAgreementsMember" abstract="true" name="MinimumVolumeCommitmentAgreementsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_EagleFordPipelineLLCMember" abstract="true" name="EagleFordPipelineLLCMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_IndictmentTotalNumberofCountsDismissed" abstract="false" name="IndictmentTotalNumberofCountsDismissed" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="pagp_GainsLossesFromDerivativeActivitiesNetofInventoryValuationAdjustments" abstract="false" name="GainsLossesFromDerivativeActivitiesNetofInventoryValuationAdjustments" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_LossContingencyPenaltyOrFineAssessed" abstract="false" name="LossContingencyPenaltyOrFineAssessed" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_TradeAccountsReceivableNetDisclosureOfMaximumAgeOfBalancesPastScheduledInvoiceDate" abstract="false" name="TradeAccountsReceivableNetDisclosureOfMaximumAgeOfBalancesPastScheduledInvoiceDate" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="pagp_TariffActivitiesNGLPipelinesMember" abstract="true" name="TariffActivitiesNGLPipelinesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_EquityIndexedCompensationExpenseAwardsThatWillOrMayBeSettledInUnits" abstract="false" name="EquityIndexedCompensationExpenseAwardsThatWillOrMayBeSettledInUnits" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_PositionsHedgingRiskofNotUtilizingStorageCapacityMember" abstract="true" name="PositionsHedgingRiskofNotUtilizingStorageCapacityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_DepreciationAndAmortizationOfUnconsolidatedEntities" abstract="false" name="DepreciationAndAmortizationOfUnconsolidatedEntities" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_DiamondPipelineLlcMember" abstract="true" name="DiamondPipelineLlcMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_FMGatheringLLCMember" abstract="true" name="FMGatheringLLCMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_InventoryCurrentAndNoncurrent" abstract="false" name="InventoryCurrentAndNoncurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_AssetImpairmentAnalysisCostOfCapitalTheoreticalMarketParticipant" abstract="false" name="AssetImpairmentAnalysisCostOfCapitalTheoreticalMarketParticipant" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="num:percentItemType"/>
  <xs:element id="pagp_WhiteCliffsPipelineLlcMember" abstract="true" name="WhiteCliffsPipelineLlcMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_CaplinePipelineCompanyLLCMember" abstract="true" name="CaplinePipelineCompanyLLCMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_EquityMethodInvestmentOwnershipPercentageSold" abstract="false" name="EquityMethodInvestmentOwnershipPercentageSold" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="num:percentItemType"/>
  <xs:element id="pagp_CounterpartyDeficienciesUnbilledAndUncollected" abstract="false" name="CounterpartyDeficienciesUnbilledAndUncollected" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_IndictmentNumberofFelonyDischargesGuiltyVerdict" abstract="false" name="IndictmentNumberofFelonyDischargesGuiltyVerdict" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="pagp_CommonUnitsAndSeriesAPreferredUnitsMember" abstract="true" name="CommonUnitsAndSeriesAPreferredUnitsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_SeniorNotesDueInFebruary2021Member" abstract="true" name="SeniorNotesDueInFebruary2021Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pagp_ScheduleOfDebtInstrumentsTable" abstract="true" name="ScheduleOfDebtInstrumentsTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="pagp_ThirdPartyEnvironmentalRecoveriesReceivedAndReceivable" abstract="false" name="ThirdPartyEnvironmentalRecoveriesReceivedAndReceivable" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_OtherLongTermDebtMember" abstract="true" name="OtherLongTermDebtMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
</xs:schema>
