ASTM_D_6377_-_15.pdf

Designation:D637715Standard Test Method forDetermination of Vapor Pressure of Crude Oil:VPCRx(Expansion Method)1This standard is issued under the fixed designation D6377;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 method covers the use of automated vaporpressure instruments to determine the vapor pressure exerted invacuum of crude oils.This test method is suitable for testingsamples that exert a vapor pressure between 25 kPa and180 kPa at 37.8 C at vapor-liquid ratios from 4:1 to 0.02:1(X=4 to 0.02).NOTE1This test method is suitable for the determination of the vaporpressure of crude oils at temperatures from 0 C to 100 C and pressuresup to 500 kPa,but the precision and bias statements(see Section 14)maynot be applicable.1.2 This test method allows the determination of vaporpressure for crude oil samples having pour points above 0 C.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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.For specificwarning statements,see 7.2.1 7.3.2.2.Referenced Documents2.1 ASTM Standards:2D323 Test Method for Vapor Pressure of Petroleum Products(Reid Method)D2892 Test Method for Distillation of Crude Petroleum(15-Theoretical Plate Column)D3700 Practice for Obtaining LPG Samples Using a Float-ing Piston CylinderD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD5191 Test Method for Vapor Pressure of Petroleum Prod-ucts(Mini Method)D5853 Test Method for Pour Point of Crude OilsD6708 Practice for Statistical Assessment and Improvementof Expected Agreement Between Two Test Methods thatPurport to Measure the Same Property of a Material3.Terminology3.1 Definitions:3.1.1 platinum resistance thermometer,ntemperaturemeasuring device constructed with a length of platinum wire,whose electrical resistance changes in relation to temperature.3.1.2 vapor-liquid ratio(V/L),nthe ratio of the vaporvolume to the liquid volume of specimen,in equilibrium,underspecified conditions.3.2 Definitions of Terms Specific to This Standard:3.2.1 dead crude oil,ncrude oil with sufficiently lowvapor pressure that,when exposed to normal atmosphericpressure at room temperature,does not result in boiling of thesample.3.2.1.1 DiscussionSampling and handling of dead crudeoils can usually be done without loss of sample integrity orother problems by using normal,non-pressurized samplecontainers such as cans.3.2.2 live crude oil,ncrude oil with sufficiently high vaporpressure that it would boil if exposed to normal atmosphericpressure at room temperature.3.2.2.1 DiscussionSampling and handling live crude oilsrequires a pressurized sample system and pressurized samplecontainers to ensure sample integrity and prevent loss ofvolatile components.3.2.3 Reid vapor pressure equivalent(RVPE),na valuecalculated by a defined correlation equation(see Eq X1.1)fromVPCR4at 37.8 C that is expected to be equivalent to the vaporpressure value obtained by Test Method D323.3.2.3.1 DiscussionAs noted in 14.3 and Appendix X1,subsection X1.2,since Eq X1.1 for estimating RVPE is notuniversally applicable to all crude oils,it is recommended toreport the VPCR4(38.7 C)result for a crude oil sample.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 Oct.1,2015.Published October 2015.Originallyapproved in 1999.Last previous edition approved in 2014 as D6377 14.DOI:10.1520/D6377-15.2For 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 3.2.4 vapor pressure of crude oil(VPCRx),nthe pressureexerted in an evacuated chamber at a vapor-liquid ratio of X:1by conditioned or unconditioned crude oil,which may containgas,air or water,or a combination thereof,where X may varyfrom 4 to 0.02.3.3 Abbreviations:3.3.1 ARV,naccepted reference value3.3.2 RVPE,nReid vapor pressure equivalent3.3.3 V/L,nvapor liquid ratio3.3.4 VPCRx,nvapor pressure of crude oil at x vaporliquid ratio4.Summary of Test Method4.1 E