Designation:D323−20aStandardTestMethodforVaporPressureofPetroleumProducts(ReidMethod)1ThisstandardisissuedunderthefixeddesignationD323;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope*1.1Thistestmethodcoversproceduresforthedetermina-tionofvaporpressure(seeNote1)ofgasoline,volatilecrudeoil,andothervolatilepetroleumproducts.1.2ProcedureAisapplicabletogasolineandotherpetro-leumproductswithavaporpressureoflessthan180kPa(26psi).1.3ProcedureBmayalsobeapplicabletotheseothermaterials,butonlygasolinewasincludedintheinterlaboratorytestprogramtodeterminetheprecisionofthistestmethod.1.4ProcedureCisformaterialswithavaporpressureofgreaterthan180kPa(26psi).1.5ProcedureDforaviationgasolinewithavaporpressureofapproximately50kPa(7psi).NOTE1—Becausetheexternalatmosphericpressureiscounteractedbytheatmosphericpressureinitiallypresentinthevaporchamber,theReidvaporpressureisanabsolutepressureat37.8°C(100°F)inkilopascals(pounds-forcepersquareinch).TheReidvaporpressurediffersfromthetruevaporpressureofthesampleduetosomesmallsamplevaporizationandthepresenceofwatervaporandairintheconfinedspace.1.6Thistestmethodisnotapplicabletoliquefiedpetroleumgasesorfuelscontainingoxygenatedcompoundsotherthanmethylt-butylether(MTBE).Fordeterminationofthevaporpressureofliquefiedpetroleumgases,refertoTestMethodD1267orTestMethodD6897.Fordeterminationofthevaporpressureofgasoline-oxygenateblends,refertoTestMethodD4953.Theprecisionforcrudeoilhasnotbeendeterminedsincetheearly1950s(seeNote3).TestMethodD6377hasbeenapprovedasamethodfordeterminationofvaporpressureofcrudeoil.IP481isatestmethodfordeterminationoftheair-saturatedvaporpressureofcrudeoil.1.7ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthese...
