ASTM_D_6849_-_13.pdf

Designation:D684913Standard Practice forStorage and Use of Liquefied Petroleum Gases(LPG)inSample Cylinders for LPG Test Methods1This standard is issued under the fixed designation D6849;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This practice covers information for the storage and useof LPG samples in standard cylinders of the type used insampling method,Practice D1265 and floating piston cylindersused in sampling method,Practice D3700.1.2 This practice is especially applicable when the LPGsample is used as a quality control(QC)reference material forLPG test methods,such as gas chromatography(GC)analysis(Test Method D2163)or vapor pressure(Test Method D6897)that use only a few mL per test,since relatively small portableDepartment of Transportation(DOT)cylinders(for example,20 lb common barbecue cylinders)can be used.This practicecan be applied to other test methods.However,test methodsthat require a large amount of sample per test(for example,manual vapor pressure Test Method D1267)will require QCvolumes in excess of 1000 L if stored in standard DOTcylinders or American Society of Mechanical Engineers(ASME)vessels.2.Referenced Documents2.1 ASTM Standards:2D1265 Practice for Sampling Liquefied Petroleum(LP)Gases,Manual MethodD1267 Test Method for Gage Vapor Pressure of LiquefiedPetroleum(LP)Gases(LP-Gas Method)D2163 Test Method for Determination of Hydrocarbons inLiquefied Petroleum(LP)Gases and Propane/PropeneMixtures by Gas ChromatographyD3700 Practice for Obtaining LPG Samples Using a Float-ing Piston CylinderD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceD6897 Test Method for Vapor Pressure of Liquefied Petro-leum Gases(LPG)(Expansion Method)3.Terminology3.1 Definitions:3.1.1 floating piston cylinder(FPC),nhigh-pressuresample container with a free-floating internal piston thateffectively divides the container into two separate compart-ments.3.1.1.1 DiscussionA floating piston cylinder is used tocollect a sample of liquid under pressure without the formationof a gaseous phase which can result in changes in thecomposition of the liquid sample.3.1.2 high-pressure sample cylinder,na container used forstorage and transportation of a sample obtained at pressuresabove atmospheric pressure.3.1.2.1 DiscussionThis type of sample cylinder,some-times called a standard 80%fill cylinder,when used for LPGtypically contains both liquid and vapor phase material.3.1.3 liquefied petroleum gas,(LP Gas,LPG),na narrowboiling range mixture of hydrocarbons consisting of propane,propylene,butanes and butylenes,individually or in specifiedcombinations,with limited amounts of other hydrocarbons andnaturally occurring non-hydrocarbons.3.1.3.1 DiscussionLPG is typically maintained in a liquidstate by containing it within a closed container or storage tankthat can withstand the vapor pressure of the LPG at ambienttemperature,or at a low temperature in refrigerated storage.3.1.4 maximum fill volume(reduced fill volume),nthevolume of a container that may be safely occupied by the liquidsample,usually expressed as a percentage of the total capacity.3.1.4.1 DiscussionSome regulatory agencies use the ex-pressions maximum fill density and reduced fill density.4.Summary of Practice4.1 This practice provides information for the design andoperation of LPG sample storage cylinders taking into accountproperties of LPG and types of cylinders in common use forstorage of LPG.1This practice is under the jurisdiction of ASTM Committee D02 on PetroleumProducts,Liquid Fuels,and Lubricants and is the direct responsibility of Subcom-mittee D02.08 on Volatility.Current edition approved June 15,2013.Published July 2013.Originallyapproved in 2002.Last previous edition approved in 2012 as D684902(2012).DOI:10.1520/D6849-13.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.2 This practice provides additional guidelines to PracticeD6299 to determine the minimum volume of LPG samplematerial required,when used as a QC reference material.5.Significance and Use5.1 LPG samples can change composition during storageand use from preferential vaporization of lighter(lower mo-lecular weight)hydrocarbon components,dissolved inert gases(N2,Ar,He,and so forth)and other dissolved gases/liquids(NH3,CO2,H2S,H2O,etc.).Careful selection of cylinder type,cylinder volume,and