ASTM_D_8420_-_21.pdf

Designation:D842021Standard Test Method forWax Appearance Temperature and Wax DisappearanceTemperature of Petroleum Products and Liquid Fuels1This standard is issued under the fixed designation D8420;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 determination of the waxappearance temperature and the wax disappearance tempera-ture of petroleum products and liquid fuels by an automaticinstrument using optical light scattering detection.1.2 This test method is applicable to such materials as:crude oil,distillate fuels,residual fuels such as No.6 Fuel Oil,marine fuels such as VLSFO,and including mixtures of thesefuels and liquid biofuels.1.3 This test method covers the range of temperatures from30 C to+75 C with temperature resolution of 0.1 C.1.4 This test method contains interim precision with repeat-ability only;a full ILS will be completed within five years ofits approval.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 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.7 This international 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)Committee.2.Referenced Documents2.1 ASTM Standards:2D4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD5773 Test Method for Cloud Point of Petroleum Productsand Liquid Fuels(Constant Cooling Rate Method)D6300 Practice for Determination of Precision and BiasData for Use in Test Methods for Petroleum Products,Liquid Fuels,and Lubricants3.Terminology3.1 Definitions:3.1.1 cloud point,nin petroleum products and biodieselfuels,the temperature of a liquid specimen when the smallestobservable cluster of wax crystals first occurs upon coolingunder prescribed conditions.3.2 Definitions of Terms Specific to This Standard:3.2.1 wax appearance temperature,WAT,nwhen the ap-pearance of wax crystals in the specimen is determined underthe conditions of this test method.3.2.1.1 DiscussionThe wax appearance temperature inthis test method is determined by an automatic instrumentusing an optical device for detection of the crystal formation.3.2.2 wax disappearance temperature,WDT,nwhen thedisappearance of wax crystals is determined under the condi-tions of this test method.3.2.2.1 DiscussionThe wax disappearance temperature inthis test method is determined by an automatic instrumentusing an optical device for detection of the crystal formation.4.Summary of Test Method4.1 A specimen in a chamber cooled by a Peltier device at aconstant rate of 1.5 C min 6 0.5 C min while continuouslybeing illuminated by a near infrared(NIR)light source.Thespecimen is continuously monitored by an array of opticaldetectors for the appearance of wax crystals.The detectors aresufficient in number to ensure that any solid phase wax crystalsthat may form are detected.The temperature at which theappearance of wax crystals is detected in the specimen,asdetermined by the apparatus,is recorded to 0.1 C resolution asthe wax appearance temperature.Once the wax appearance1This 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.Current edition approved Nov.1,2021.Published December 2021.DOI:10.1520/D8420-21.2For 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 StatesThis 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 Trade(TBT)Committee.1?temperature is detected,when the wax disappearance tempera-ture is desired,the specimen is warmed at a constant rate of1.5 Cmin 6 0.5 C min while continuously being illumi-nated by a NIR light source until the crystals in the spec