Designation:D7157−22´1StandardTestMethodforDeterminationofIntrinsicStabilityofAsphaltene-ContainingResidues,HeavyFuelOils,andCrudeOils(n-HeptanePhaseSeparation;OpticalDetection)1ThisstandardisissuedunderthefixeddesignationD7157;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ε1NOTE—EditorialcorrectionsmadethroughoutinSeptember2022.1.Scope*1.1Thistestmethodcoversaprocedureforquantifyingtheintrinsicstabilityoftheasphaltenesinanoilbyanautomaticinstrumentusinganopticaldevice.1.2Thistestmethodisapplicabletoresidualproductsfromthermalandhydrocrackingprocesses,toproductstypicalofSpecificationsD396GradesNo.5L,5H,and6,andD2880GradesNo.3-GTand4-GT,andtocrudeoils,providingtheseproductscontain0.5%bymassorgreaterconcentrationofasphaltenes(seeTestMethodD6560).1.3Thistestmethodquantifiesasphaltenestabilityintermsofstateofpeptizationoftheasphaltenes(S-value),intrinsicstabilityoftheoilymedium(So)andthesolvencyrequirementsofthepeptizedasphaltenes(Sa).1.4ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.1.6Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2D396SpecificationforFuelOilsD2880SpecificationforGasTurbineFuelOilsD4057PracticeforManualSamplingofPetroleumandPetroleumProductsD4175TerminologyRelating...
