Designation:D7975−14StandardTestMethodforDeterminationofVaporPressureofCrudeOil:VPCRx-F(Tm°C)(ManualExpansionFieldMethod)1ThisstandardisissuedunderthefixeddesignationD7975;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoverstheuseofmanualvaporpressureinstrumentstodeterminethevaporpressureofcrudeoilsexertedinavacuum.Thistestmethodissuitablefortestingsamplesthatexertavaporpressurebetween25kPaand180kPaat37.8°Catvapor/liquidratiosfrom4:1to0.25:1(X=4to0.25,see3.2.4).NOTE1—Thistestmethodissuitableforthedeterminationofthevaporpressureofcrudeoilsattemperaturesfrom0°Cto60°Candpressuresupto500kPa,buttheprecisionandbiasstatements(seeSection15)maynotbeapplicable.1.2Thistestmethodismeantprimarilyforuseunderfieldconditionsforimmediateevaluationofvaporpressureforstorage,transport,oroperationaluses.1.3Thistestmethodisnotintendedforuseincustodytransferapplications.TestMethodD6377shallbeusedforcustodytransferapplications.1.4Thistestmethodprovidesareasonableconfirmationforthepresenceoflightendsinthesourcematerialgiventhatthepartialpressureoflowboilingcomponentscontributesignifi-cantlytototalvaporpressure.1.5Thistestmethodallowsbothsamplecollectionandsubsequentvaporpressuremeasurementofcrudeoilsamplesdirectlyfromthesamplesource.ThecollectedsamplemayalsobetransferredtoanautomatedvaporpressureinstrumentsuchasusedforTestMethodD6377.Thefieldtestapparatusissuitablefortransportationprovidedsuitableover-packisusedtomeettheregulationsforthetransportationofdangerousgoodsinthetransportationjurisdiction(s).1.6Thistestmethodallowsthedeterminationofvaporpressureforcrudeoilsampleshavingpourpointsbelow0°Candflowatthesamplingconditionstoallowinlettotheapparatus.1.7ThevaluesstatedinSIunitsaretoberegardedasstandard.1.7.1Exception—Otherunitsofmeasurementareinclud...
