Designation:D3956−12(Reapproved2018)StandardSpecificationforMethaneThermophysicalPropertyTables1ThisstandardisissuedunderthefixeddesignationD3956;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thethermophysicalpropertytablesformethaneareforuseinthecalculationofthepressure-volume-temperature(PVT),thermodynamic,andtransportpropertiesofmethaneforprocessdesignandoperations.Threetablesareprovidedforgaseousandliquidmethaneattemperaturesbetween90Kand600Katpressuresto30MPa.Twotablesprovidepropertiesfortheliquidandvaporphasesatliquid-vaporequilibrium(satu-rationproperties).Thethirdtableprovidespropertiesatse-lectedT,ppointsfortheequilibriumphaseatthoseconditions.ThetablesweredevelopedbytheNationalInstituteofStan-dardsandTechnologyfromaStandardReferenceDatabaseproductREFPROP,version9.0.1.2Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.Applicability2.1Thesetablesapplydirectlyonlytopuregaseousmeth-ane.However,itisexpectedthattheymayfindsubstantialuseinmathematicalmodelsandtablesforthethermophysicalpropertiesofmixturescontainingmethane.3.Tables3.1ThermophysicalPropertiesofMethaneLiquidatLiquid-VaporEquilibrium,inSIunits.3.2ThermophysicalPropertiesofMethaneVaporatLiquid-VaporEquilibrium,inSIunits.3.3ThermophysicalPropertiesofMethaneAlongIsobars,inSIunits.3.4Thetabulatedpropertiesare:ρ=molardensity(mol·L-1)H=molarenthalpy(J·mol-1)S=molarentropy(J·K-1·mol-1)Cv=constantvolumemolarheatcapacity(J·K-1·mol-1)Cp=constantpressuremolarheatcapacity(J·K-1·mol-1)c=speedofsound(m·s-1)η=viscosity(µPa·s)λ=thermalconductivity(mW·...
