ASTM_D_2420_-_13.pdf

Designation:D242013Standard Test Method forHydrogen Sulfide in Liquefied Petroleum(LP)Gases(LeadAcetate Method)1This standard is issued under the fixed designation D2420;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 test method2covers the detection of hydrogensulfide in liquefied petroleum(LP)gases.The sensitivity of thetest is about 4 mg/m3(0.15 to 0.2 grain of hydrogen sulfide per100 ft3)of gas.1.2 The values stated in SI units are to be regarded asstandard.The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:3D1193 Specification for Reagent WaterD1265 Practice for Sampling Liquefied Petroleum(LP)Gases,Manual MethodD1835 Specification for Liquefied Petroleum(LP)Gases2.2 GPA Standard:4GPA 2140 Liquefied Petroleum Gas Specifications and TestMethods3.Summary of Test Method3.1 Vaporized LPgas is passed over moist lead acetate paperunder controlled conditions.Hydrogen sulfide reacts with leadacetate to form lead sulfide which produces a coloration on thepaper varying from yellow to black,depending upon theamount of hydrogen sulfide present.4.Significance and Use4.1 Liquefied petroleum gases and their products of com-bustion must not be unduly corrosive to the materials withwhich they come in contact.The potential personnel exposurehazards of H2S also make the detection and measurement ofhydrogen sulfide important,even in low concentrations.Inaddition,in some cases the odor of the gases shall not beobjectionable.(See Specification D1835 and GPA 2140.)5.Interferences5.1 Methyl mercaptan,if present,produces a transitoryyellow stain on the lead acetate paper that will fade completelyin less than 5 min.5.2 Other sulfur compounds present in liquefied petroleumgas do not interfere with the test.6.Apparatus and Materials6.1 Apparatus for Detecting Hydrogen Sulfide in LiquefiedPetroleum Gas,as shown in Fig.1 or commercially availableapparatus.6.2 Lead Acetate Test PaperCommercially available testpaper is satisfactory.Alternatively,the test paper may beprepared by dipping strips of smooth filter paper in 5%aqueous lead acetate solution and removing the excess solutionwith a clean blotter.The strips of paper shall be approximately50 mm long and 10 mm wide and contain a 3 mm hole near oneend so they will hang freely vertical in the test apparatus.6.3 Gas Flow IndicatorCapable of measuring flow ratesin the range of 2 to 3 L of gas per minute.A wet test meterrotameter and mass flow controller have been found to besuitable.6.4 WaterUnless otherwise indicated,reference to watershall be understood to mean reagent water that meets therequirements of Type II or III of Specification D1193,ordistilled water.6.5 TubingHighpressure connecting tubing to connectthe test apparatus to the sample collection point.Internallyclean,non-reactive and non-absorptive stainless steel material1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.H0 on Liquefied Petroleum Gas.Current edition approved June 15,2013.Published July 2013.Originallyapproved in 1965.Last previous edition approved in 2012 as D2420 12a.DOI:10.1520/D2420-13.2This test method is based on Edwards,J.D.,and McBride,R.S.,“LeadAcetateTest for Hydrogen Sulphide in Gas,”Technologic Papers T41,National Institute forStandards and Technology,Aug.9,1914.3For 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.4Available from Gas Processors Association(GPA),6526 E.60th St.,Tulsa,OK74145,www.gpaglobal.org.*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 is recommended,but other materials that safely contain thepressure,resist being cut or torn,and have been tested to beinert relative to the stream being tested may be utilized.6.5.1 Internal surfaces of sample containers,lines and fit-tings may be surface coated with an inert material to reducebare metal surfaces which could react with,or absorb,tracehydrogen sulfide.56.6 HighPressure Sample Container,optionalDesignedfor containing liquefied petroleum gas.An inert surface coatingon the inner surface of the container may be used,and isrecommended.7.Sampling7.1 Colle