Designation:D4921−20StandardTestMethodforFoamingTendenciesofEngineCoolantsatRoomTemperature1ThisstandardisissuedunderthefixeddesignationD4921;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodappliestoasimpleshaketestforevaluatingthetendencyofanaqueoussolutionofenginecoolanttofoamatroomtemperature.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.1.4Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2D1176PracticeforSamplingandPreparingAqueousSolu-tionsofEngineCoolantsorAntirustsforTestingPurposes3.SummaryofTestMethod3.1A30%byvolumecoolantconcentratesolutionispreparedindeionizedwaterandshakeninastopperedgradu-atedcylinderfor30s.Thevolumeoffoamformedinthecylinderisreadinmillilitres.PreparationofthesampleisdoneinaccordancewithPracticeD1176.4.SignificanceandUse4.1Thetestmethodwillgenerallyidentifycoolantsthathaveatendencytofoamexcessivelyatroomtemperature.NOTE1—Inuse,thefoamingtendencyofacoolantsolutionmaybeincreasedbyserviceagingorcontamination.5.Apparatus5.1GraduatedCylinders—100mLgraduatedcylinderswithplasticstoppersarepreferredforeaseofhandling.5.2WaterBath—Awaterbathorequivalentdevicecapableofmaintainingtemperatureat22.5°C62.5°C.6.Reagents6.1DeionizedWater.7.T...
