Designation:D6743−11(Reapproved2015)StandardTestMethodforThermalStabilityofOrganicHeatTransferFluids1ThisstandardisissuedunderthefixeddesignationD6743;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthedeterminationofthethermalstabilityofunusedorganicheattransferfluids.Theprocedureisapplicabletofluidsusedforthetransferofheatattempera-turesbothaboveandbelowtheirboilingpoint(referstonormalboilingpointthroughoutthetextunlessotherwisestated).Itisapplicabletofluidswithmaximumbulkoperatingtemperaturebetween260°C(500°F)and454°C(850°F).Theprocedureshallnotbeusedtotestafluidaboveitscriticaltemperature.Inthistestmethod,thevolatiledecompositionproductsareincontinuouscontactwiththefluidduringthetest.Thistestmethodwillnotmeasurethethermalstabilitythreshold(thetemperatureatwhichvolatileoilfragmentsbegintoform),butinsteadwillindicatebulkfragmentationoccurringforaspeci-fiedtemperatureandtestingperiod.Becausepotentialdecom-positionandgenerationofhighpressuregasmayoccurattemperaturesabove260°C(500°F),donotusethistestmethodforaqueousfluidsorotherfluidswhichgeneratehigh-pressuregasatthesetemperatures.1.2DINNorm51528coversatestmethodthatissimilartothistestmethod.1.3Theapplicabilityofthistestmethodtosiloxane-basedheattransferfluidshasnotbeendetermined.1.4ThevaluesstatedinSIunitsaretoberegardedasstandard.Thevaluesgiveninparenthesesareforinformationonly.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.Forspecificwarningstatements,see7.2,8.8,8.9,and8.10.2.ReferencedDocuments2.1ASTMStandards:2D2887TestMethodforBoilingRangeDistributionofPe-troleumFractionsbyG...
