1、Designation:D518814Standard Test Method forVapor-Liquid Ratio Temperature Determination of Fuels(Evacuated Chamber and Piston Based Method)1This standard is issued under the fixed designation D5188;the number immediately following the designation indicates the year oforiginal adoption or,in the case
2、 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 method covers the determination of the tem-perature at which the vapor formed from a se
3、lected volume ofvolatile petroleum product saturated with air at 0 C to 1 C(32 F to 34 F)produces a pressure of 101.3 kPa(oneatmosphere)against vacuum.This test method is applicable tosamples for which the determined temperature is between36 C and 80 C(97 F and 176 F)and the vapor-liquid ratiois bet
4、ween 8 to 1 and 75 to 1.NOTE1When the vapor-liquid ratio is 20:1,the result is intended tobe comparable to the results determined by Test Method D2533.NOTE2This test method may also be applicable at pressures otherthan one atmosphere,but the stated precision may not apply.1.2 This test method is app
5、licable to both gasoline andgasoline-oxygenate blends.1.2.1 Some gasoline-oxygenate blends may show a hazewhen cooled to 0 C to 1 C.If a haze is observed in 12.5,itshall be indicated in the reporting of results.The precision andbias statements for hazy samples have not been determined(see Note 10).1
6、.3 The values stated in SI units are to be regarded asstandard.The values given in parentheses are provided forinformation only.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 app
7、ro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.For specificwarnings,see 7.2 and 8.1.1.2.Referenced Documents2.1 ASTM Standards:2D2533 Test Method for Vapor-Liquid Ratio of Spark-Ignition Engine Fuels(Withdrawn 2008)3D2892 Test Method for
8、 Distillation of Crude Petroleum(15-Theoretical Plate Column)D4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceD6708 Practice for Statistica
9、l Assessment and Improvementof Expected Agreement Between Two Test Methods thatPurport to Measure the Same Property of a Material3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 T(V/L=20),nthe equilibrium temperature at whichthe partial pressure of a sample under test conditions
10、 is equalto 101.3 kPa(14.69 psia)and the vapor-liquid ratio is 20.3.1.2 vapor-liquid ratio of a fuel,nthe ratio at a specifiedtemperature and pressure of the volume of vapor in equilibriumwith liquid to the volume of sample charged,as a liquid,at0 C(32 F).4.Summary of Test Method4.1 A known volume o
11、f chilled,air-saturated sample isintroduced into an evacuated,thermostatically controlled testchamber of known volume or a test chamber with moveablepiston that expands the volume after sample introduction,theinternal volume of which is V/L+1 times of that of the total testspecimen introduced into t
12、he chamber.The sample volume iscalculated to give the desired vapor-liquid ratio for the cham-ber volume in use.After injection,the chamber temperature isadjusted until a stable chamber pressure of 101.3 kPa(14.69psia)is achieved.5.Significance and Use5.1 The tendency of a fuel to vaporize in automo
13、tive enginefuel systems is indicated by the vapor-liquid ratio of the fuel.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.08 on Volatility.Current edition approved Jan.1,2014.Publi
14、shed March 2014.Originallyapproved in 1991.Last previous edition approved in 2013 as D518813.DOI:10.1520/D5188-14.2For 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 sta
15、ndards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.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 S
16、tates1 5.2 Automotive fuel specifications generally include T(V/L=20)limits to ensure products of suitable volatility perfor-mance.For high ambient temperatures,a fuel with a high valueof T(V/L=20),indicating a fuel with a low tendency to vaporize,isgenerallyspecified;converselyforlowambienttemperatures,a fuel with a low value of T(V/L=20)is specified.6.Apparatus6.1 Apparatus suitable for use shall employ a small volumetest chamber incorporating a transducer for pressure measure-ments and associ
