Designation:D3700−21StandardPracticeforObtainingLPGSamplesUsingaFloatingPistonCylinder1ThisstandardisissuedunderthefixeddesignationD3700;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thispracticecoverstheequipmentandproceduresforobtainingarepresentativesampleofliquefiedpetroleumgas(LPG),suchasspecifiedinASTMSpecificationD1835,GPA2140,andcomparableinternationalstandards.Itmayalsobeusedforothernaturalgasliquid(NGL)productsthatarenormallysinglephase(forexample,NGLmix,fieldbutane,andsoforth),definedinotherindustryspecificationsorcontractualagreements,andforvolatile(highervaporpres-sure)crudeoils.NOTE1—Somefloatingpistoncylindershavesuchtightpistonsealsthatthevaporpressureofsomehighvaporpressurecrudeoilsmaynotbesufficienttoallowsamplingwithoutahandletomovethepiston.AnalternativesamplingpracticeforUNClass3liquids(under300kPaat52°C)isPracticeD8009,whichutilizesaManualPistonCylinder(MPC)sampler.1.2Thispracticeisnotintendedfornon-specificationprod-uctsthatcontainsignificantquantitiesofundissolvedgases(N2,CO2),freewaterorotherseparatedphases,suchasraworunprocessedgas/liquidsmixturesandrelatedmaterials.Thesameequipmentcanbeusedforthesepurposes,butadditionalprecautionsaregenerallyneededtoobtainrepresentativesamplesofmulti-phaseproducts(seeAppendixX1).1.3Thispracticeincludesrecommendationsforthelocationofasamplepointinalineorvessel.Itistheresponsibilityoftheusertoensurethatthesamplingpointislocatedsoastoobtainarepresentativesample.1.4ThevaluesstatedinSIunitsaretoberegardedasstandard.1.4.1Exception—Thevaluesgiveninparenthesesareforinformationonly.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpractices,anddeter-minethea...
