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  <xs:element id="pagp_AnticipatedNetSalesOfInventoryMember" abstract="true" name="AnticipatedNetSalesOfInventoryMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pagp_ContractsRelatedToNaturalGasPurchasesMember" abstract="true" name="ContractsRelatedToNaturalGasPurchasesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pagp_PropaneContractsRelatedToSubsequentSaleOfProductMember" abstract="true" name="PropaneContractsRelatedToSubsequentSaleOfProductMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pagp_ButaneContractsRelatedToSubsequentSaleOfProductMember" abstract="true" name="ButaneContractsRelatedToSubsequentSaleOfProductMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pagp_CondensateContractsRelatedToSubsequentSaleOfProductMemberMember" abstract="true" name="CondensateContractsRelatedToSubsequentSaleOfProductMemberMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pagp_FuelGasRequirementsContractsMember" abstract="true" name="FuelGasRequirementsContractsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pagp_PowerSupplyRequirementsContractsMember" abstract="true" name="PowerSupplyRequirementsContractsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pagp_FieldOperatingCostsMember" abstract="true" name="FieldOperatingCostsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1: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_OffsettingAssetsLiabilitiesLineItems" abstract="true" name="OffsettingAssetsLiabilitiesLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <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_VariationMarginPostedReturned" abstract="false" name="VariationMarginPostedReturned" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_EightForwardStartingThirtyYearInterestRateSwaps309PercentMember" abstract="true" name="EightForwardStartingThirtyYearInterestRateSwaps309PercentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pagp_FourForwardStartingThirtyYearInterestRateSwaps074PercentMember" abstract="true" name="FourForwardStartingThirtyYearInterestRateSwaps074PercentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pagp_Line901IncidentMember" abstract="true" name="Line901IncidentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pagp_Line9012015InsuranceProgramMember" abstract="true" name="Line9012015InsuranceProgramMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pagp_Line48IncidentMember" abstract="true" name="Line48IncidentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pagp_ArbitrationProceedingsAgainstInsurersMember" abstract="true" name="ArbitrationProceedingsAgainstInsurersMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pagp_CurrentLiabilitiesMember" abstract="true" name="CurrentLiabilitiesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pagp_InsuranceCoverageLimit" abstract="false" name="InsuranceCoverageLimit" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_EstimatedSizeOfRelease" abstract="false" name="EstimatedSizeOfRelease" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:volumeItemType"/>
  <xs:element id="pagp_LossContingencySelfInsuredRetention" abstract="false" name="LossContingencySelfInsuredRetention" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_LossContingencyCleanUpAndRemediateAggregateCost" abstract="false" name="LossContingencyCleanUpAndRemediateAggregateCost" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_LossContingencyCleanUpAndRemediationActivities" abstract="false" name="LossContingencyCleanUpAndRemediationActivities" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_GeneralAndAdministrativeExpenseExcludingUnallocatedAmount" abstract="false" name="GeneralAndAdministrativeExpenseExcludingUnallocatedAmount" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_SignificantSegmentExpenses" abstract="false" name="SignificantSegmentExpenses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <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_GainsLossesFromDerivativeActivitiesAndInventoryValuationAdjustments" abstract="false" name="GainsLossesFromDerivativeActivitiesAndInventoryValuationAdjustments" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <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_DeficienciesUnderMinimumVolumeCommitmentsNet" abstract="false" name="DeficienciesUnderMinimumVolumeCommitmentsNet" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_EquityIndexedCompensationExpenseAwardsThatWillBeSettledInUnits" abstract="false" name="EquityIndexedCompensationExpenseAwardsThatWillBeSettledInUnits" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_NetGainLossOnForeignCurrencyRevaluation" abstract="false" name="NetGainLossOnForeignCurrencyRevaluation" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_TransactionRelatedExpenses" abstract="false" name="TransactionRelatedExpenses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_SegmentAmountsAttributableToNoncontrollingInterests" abstract="false" name="SegmentAmountsAttributableToNoncontrollingInterests" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <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_InvestmentAndAcquisitionCapitalExpenditures" abstract="false" name="InvestmentAndAcquisitionCapitalExpenditures" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_MaintenanceCapitalExpenditures" abstract="false" name="MaintenanceCapitalExpenditures" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_EnCapFlatrockMidstreamMember" abstract="true" name="EnCapFlatrockMidstreamMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pagp_TheEnergyMineralsGroupMember" abstract="true" name="TheEnergyMineralsGroupMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pagp_IronwoodMidstreamEnergyPartnersIILLCMember" abstract="true" name="IronwoodMidstreamEnergyPartnersIILLCMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pagp_EMGMedallion2HoldingsMember" abstract="true" name="EMGMedallion2HoldingsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pagp_CheyennePipelineLLCMember" abstract="true" name="CheyennePipelineLLCMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pagp_BusinessCombinationMeasurementInput" abstract="false" name="BusinessCombinationMeasurementInput" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="pagp_BusinessCombinationConsiderationTransferredNetToOwnershipInterest" abstract="false" name="BusinessCombinationConsiderationTransferredNetToOwnershipInterest" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pagp_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedWorkingCapitalAndOtherAssetsAndLiabilities" abstract="false" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedWorkingCapitalAndOtherAssetsAndLiabilities" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
</xs:schema>
