ASTM_D_7975_-_14.pdf

Designation:D797514Standard Test Method forDetermination of Vapor Pressure of Crude Oil:VPCRx-F(TmC)(Manual Expansion Field Method)1This standard is issued under the fixed designation D7975;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 use of manual vaporpressure instruments to determine the vapor pressure of crudeoils exerted in a vacuum.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 0.25:1(X=4 to 0.25,see 3.2.4).NOTE1This test method is suitable for the determination of the vaporpressure of crude oils at temperatures from 0 C to 60 C and pressures upto 500 kPa,but the precision and bias statements(see Section 15)may notbe applicable.1.2 This test method is meant primarily for use under fieldconditions for immediate evaluation of vapor pressure forstorage,transport,or operational uses.1.3 This test method is not intended for use in custodytransfer applications.Test Method D6377 shall be used forcustody transfer applications.1.4 This test method provides a reasonable confirmation forthe presence of light ends in the source material given that thepartial pressure of low boiling components contribute signifi-cantly to total vapor pressure.1.5 This test method allows both sample collection andsubsequent vapor pressure measurement of crude oil samplesdirectly from the sample source.The collected sample mayalso be transferred to an automated vapor pressure instrumentsuch as used for Test Method D6377.The field test apparatusis suitable for transportation provided suitable over-pack isused to meet the regulations for the transportation of dangerousgoods in the transportation jurisdiction(s).1.6 This test method allows the determination of vaporpressure for crude oil samples having pour points below 0 Cand flow at the sampling conditions to allow inlet to theapparatus.1.7 The values stated in SI units are to be regarded asstandard.1.7.1 ExceptionOther units of measurement are includedin this standard for ease of use in multiple jurisdictions.1.8 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:2D323 Test Method for Vapor Pressure of Petroleum Products(Reid Method)D1193 Specification for Reagent WaterD5191 Test Method for Vapor Pressure of Petroleum Prod-ucts(Mini Method)D5853 Test Method for Pour Point of Crude OilsD6377 Test Method for Determination of Vapor Pressure ofCrude Oil:VPCRx(Expansion Method)3.Terminology3.1 Definitions:3.1.1 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,na term usually employed for crudeoils that,when exposed to normal atmospheric pressure atroom temperature,will not result in actual boiling of thesample.3.2.1.1 DiscussionThese crudes will have vapor pressuresbelow atmospheric pressure at room temperature.3.2.1.2 DiscussionThis method will provide vapor pres-sure information that will allow the user to determine if a crudeoil is considered“dead”or“live.”A crude oil shall always beconsidered“live”until the vapor pressure can be established.Sampling and handling of dead crude oils can usually be done1This 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 Dec.1,2014.Published February 2015.DOI:10.1520/D7975-14.2For 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 standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 without concern in normal,non-pressurized sample containers,such as cans and other atmospheric containers.3.2.2 light ends,ncomponents that cannot be maintainedas a liquid at atmospheric pressure at temperatures greater than0 C.3.2.2.1 DiscussionThis includes any materials that haveatmospheric boiling points below 0 C including methane,ethane,propane,butane,and fixed gases such as H2S,CO2,N2,O2,H2,CO.3.2.3 live crude oil,na term usually employed for crudeoils contained in pressurized systems that,when brought tonormal atmospheric pressure at room temperature,will resultin actual boiling of the sample.