1、Designation:D734615Standard Test Method forNo Flow Point and Pour Point of Petroleum Products andLiquid Fuels1This standard is issued under the fixed designation D7346;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last
2、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 no flowpoint and pour point of petroleum products,liquid fuels,biodiesel,and b
3、iodiesel blends using an automatic instrument.1.2 The measuring range of the apparatus is from 95 C to45 C,however the precision statements were derived onlyfrom samples with no flow point temperatures from 77 C to+2 C and samples with pour point in the temperature range of58 C to+12 C.1.3 Pour poin
4、t results from this test method can be reportedat 1 C or 3 C intervals.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It
5、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:2D97 Test Method for Pour Point of Petroleum ProductsD4057 Practice for Manual Samp
6、ling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD6300 Practice for Determination of Precision and BiasData for Use in Test Methods for Petroleum Products andLubricantsD6708 Practice for Statistical Assessment and Improvementof Expected A
7、greement Between Two Test Methods thatPurport to Measure the Same Property of a Material3.Terminology3.1 Definitions:3.1.1 pour point,nin petroleum products,the lowesttemperature at which movement of the test specimen isobserved under the prescribed conditions of the test.3.2 Definitions of Terms Sp
8、ecific to This Standard:3.2.1 no-flow point,nin petroleum products,the tempera-ture of the test specimen at which a wax crystal structureformation or viscosity increase,or both,is sufficient to impedemovement of the surface of the test specimen under theconditions of the test.3.2.1.1 DiscussionThe n
9、o-flow point occurs when,uponcooling,the formation of wax crystal structures or viscosityincrease,or both,have progressed to the point where theapplied observation device no longer detects movement underthe conditions of the test.4.Summary of Test Method4.1 After inserting the test specimen into the
10、 automatic noflow point apparatus and initiating the program,the testspecimen is heated,if necessary,to a starting temperature andthen cooled by prescribed rates.The test specimen is continu-ously tested for flow characteristics by continuously monitor-ing the air pressure variation inside the test
11、specimen vial.When the specimen is still fluid,its movement will partiallycompensate for the reduction in air pressure in the test chamberabove the test specimen surface.At some temperature thepressure measuring system detects a pressure decrease due toincapability of the test specimen to flow cause
12、d by a crystalstructure formation in the specimen or its viscosity increase,orboth.This temperature is recorded as no flow point with aresolution of 0.1 C.The pour point is recorded by roundingthe no flow point temperature to either the next warmer 1 Cinterval or 3 C interval.The test specimen is th
13、en reheated toallow for removal from the test chamber.5.Significance and Use5.1 The no flow point of a petroleum product is an index ofthe lowest temperature of its utility for some applications.Flow1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,a
14、nd Lubricants and is the direct responsibility ofSubcommittee D02.07 on Flow Properties.Current edition approved July 1,2015.Published July 2015.Originally approvedin 2007.Last previous edition approved in 2014 as D7346 14.DOI:10.1520/D7346-15.2For referenced ASTM standards,visit the ASTM website,ww
15、w.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
16、 C700,West Conshohocken,PA 19428-2959.United States1 characteristics,such as no flow point,can be critical for theproper operation of lubricating systems,fuel systems,andpipeline operations.5.2 Petroleum blending operations require precise measure-ment of the no flow point.5.3 This test method can determine the temperature of thetest specimen with a resolution of 0.1 C at which eithercrystals have formed or viscosity has increased sufficiently,orboth,to impede flow of the petroleum product.5.4 T
