ASTM_D_7667_-_10_2015.pdf

Designation:D766710(Reapproved 2015)Standard Test Method forDetermination of Corrosiveness to Silver by AutomotiveSpark-Ignition Engine FuelThin Silver Strip Method1This standard is issued under the fixed designation D7667;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.Scope1.1 This test method covers the determination of the corro-siveness to silver by automotive spark-ignition engine fuel(forexample,gasoline),as defined by Specification D4814 orsimilar specifications in other jurisdictions,having a vaporpressure no greater than 124 kPa(18 psi)at 37.8 C(100 F)by one of two procedures.1.1.1 Procedure AInvolves the use of a pressure vessel.1.1.2 Procedure BInvolves the use of a vented test tube.1.2 The values stated in SI units are to be regarded as thestandard.The values in parentheses are for information only.1.3 WARNINGMercury has been designated by manyregulatory agencies as a hazardous material that can causecentral nervous system,kidney and liver damage.Mercury,orits vapor,may be hazardous to health and corrosive tomaterials.Caution should be taken when handling mercury andmercury containing products.See the applicable product Ma-terial Safety Data Sheet(MSDS)for details and EPAswebsitehttp:/www.epa.gov/mercury/faq.htmfor addi-tional information.Users should be aware that selling mercuryand/or mercury containing products into your state or countrymay be prohibited by law.1.4 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:2D130 Test Method for Corrosiveness to Copper from Petro-leum Products by Copper Strip TestD3241 Test Method for Thermal Oxidation Stability ofAviation Turbine FuelsD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD4814 Specification for Automotive Spark-Ignition EngineFuelE1 Specification for ASTM Liquid-in-Glass Thermometers2.2 Energy Institute Standards:3IP 227 Determination of Corrosiveness to Silver of AviationTurbine Fuels-Silver Strip Method2.3 ASTM Adjuncts:4Color standard for tube deposit rating(5 aluminum strips)3.Terminology3.1 Abbreviations:PTFE=polytetrafluoroethylenePV=pressure vesselPVP=pressure vessel procedureSSCD=silver strip centering deviceTSMD=temperature sensing and monitoring deviceVTTP=vented test tube procedure4.Summary of Test Method4.1 A polished,thin silver strip is immersed in 30 mL of thesample being tested,and heated at 50 C(122 F)for 2 h.Atthe end of the heating period,the silver strip is removed,washed,and the color and tarnish level assessed against theSilver Strip Classifications in Table 1.5.Significance and Use5.1 Crude petroleum contains sulfur compounds,most ofwhich are removed during refining.However,of the sulfurcompounds remaining in the petroleum product or introducedinto the fuel during storage and distribution,some can have a1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.05.0C on Color and Reactivity.Current edition approved Oct.1,2015.Published December 2015.Originallyapproved in 2010.Last previous edition approved in 2010 as D7667 102.DOI:10.1520/D7667-10R15.2For 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.3Available from Energy Institute,61 New Cavendish St.,London,WIG 7AR,U.K.,http:/www.energyinst.org.uk.4Available from ASTM International Headquarters.Order Adjunct No.ADJD3241.Original adjunct produced in 1986.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 corroding action on various metals and this corrosivity is notnecessarily related directly to the total sulfur content.Theeffect can vary according to the chemical types of sulfurcompounds present.The silver strip corrosion test is designedto assess the relative degree of corrosivity of a petroleumproduct towards silver and silver alloys.5.2 Under some circumstances,reactive sulfur compoundspresent in automotive spark-ignition engine fuels can tarnish oreven corrode silver alloy fuel gauge in-tank sender units orsilver-plated bearings(in 2-stroke cycle engines).To minimizeor prevent the failure of silver alloy in-tank sender units bytarnish or corrosion,Specification D4814 requires that fuelsshall pass a silver strip corrosi