1、Designation:D674902(Reapproved 2018)Standard Test Method forPour Point of Petroleum Products(Automatic Air PressureMethod)1This standard is issued under the fixed designation D6749;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the
2、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.INTRODUCTIONThis test method covers an alternative procedure for the determination of pour point of petroleumproducts using an
3、 automatic apparatus.1.Scope1.1 This test method covers the determination of pour pointof petroleum products by an automatic apparatus that applies aslightly positive air pressure onto the specimen surface whilethe specimen is being cooled.1.2 This test method is designed to cover the range oftemper
4、atures from 57 C to+51 C;however,the range oftemperatures included in the(1998)interlaboratory test pro-gram only covered the temperature range from 51 C to11 C.1.3 Test results from this test method can be determined ateither 1 C or 3 C testing intervals.1.4 This test method is not intended for use
5、 with crude oils.NOTE1The applicability of this test method on residual fuel sampleshas not been verified.For further information on the applicability,refer to13.4.1.5 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.6 This stan
6、dard 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.7 This internat
7、ional standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committ
8、ee.2.Referenced Documents2.1 ASTM Standards:2D97 Test Method for Pour Point of Petroleum ProductsD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum Products2.2 Energy Institute Standard:IP 15 Test Method for Pour Point
9、 of Petroleum Products33.Terminology3.1 Definitions:3.1.1 pour point,nin petroleum products,lowest tempera-ture at which movement of the test specimen is observed underprescribed conditions of test.3.2 Definitions of Terms Specific to This Standard:3.2.1 air pressure,nregulated slightly positive air
10、 pres-sure gently applied onto the specimen surface in the airtighttest jar that causes upward movement of the specimen in thecommunicating tube,which has one end inserted into the testspecimen and the other end at atmospheric pressure.3.2.2 no-flow point,nin petroleum products,temperatureof the tes
11、t specimen at which a wax crystal structure of the testspecimen or viscosity increase,or both,impedes movement ofthe surface of the test specimen under the conditions of the test.3.2.2.1 DiscussionThe no-flow point occurs when,uponcooling,the formation of wax crystal structures or viscosityincrease,
12、or both,has progressed to the point where the appliedobservation device no longer detects movement under the1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.07 on Flow Properties.Cur
13、rent edition approved May 1,2018.Published June 2018.Originallyapproved in 2002.Last previous edition approved in 2012 as D6749 02(2012).DOI:10.1520/D6749-02R18.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of AS
14、TMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from Energy Institute,61 New Cavendish St.,London,W1G 7AR,U.K.,http:/www.energyinst.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United Stat
15、esThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trad
16、e(TBT)Committee.1 conditions of the test.The preceding observation temperature,at which flow of the test specimen is last observed,is the pourpoint.4.Summary of Test Method4.1 After inserting the test jar containing the specimen intothe automatic pour point apparatus and initiating the testprogram,the specimen is automatically heated to the desig-nated temperature and then cooled at a controlled rate.Attemperature intervals of 1 C or 3 C,depending on theselection made by the user prior to the te
