ASTM_D_5901_-_03.pdf

Designation:D 5901 03Designation:434/98An American National StandardStandard Test Method forFreezing Point of Aviation Fuels(Automated OpticalMethod)1This standard is issued under the fixed designation D 5901;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(e)indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method covers the determination of the tem-perature below which solid hydrocarbon crystals may form inaviation turbine fuels.NOTE1This test method describes an alternative procedure andautomated apparatus which mimics the apparatus and procedure describedin Test Method D 2386.1.2 The measuring range of the apparatus is from 0 to70C.The precision statements were derived from sampleswith freezing point temperatures from 45 to 65C.NOTE2Typical aviation fuel has freezing point temperatures in the40 to 65C range.Samples with higher freezing points were notavailable for the current interlaboratory program.1.3 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.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 Section 7.2.Referenced Documents2.1 ASTM Standards:D 2386 Test Method for Freezing Point of Aviation Fuels2D 4057 Practice for Manual Sampling of Petroleum andPetroleum Products3D 4177 Practice for Automatic Sampling of Petroleum andPetroleum Products3E 1 Specification for ASTM Thermometers43.Terminology3.1 Definitions:3.1.1 freezing point,nin aviation fuels,the fuel tempera-ture at which solid hydrocarbon crystals,formed on cooling,disappear when the temperature of the fuel is allowed to riseunder specified conditions of test.3.2 Definitions of Terms Specific to This Standard:3.2.1 automated method,nthe robotic automation of amanual procedure and apparatus.4.Summary of Test Method4.1 After insertion of 25 mL of the test specimen into a testchamber,the test specimen is cooled while being continuouslystirred and monitored by an optical system.The temperature ofthe specimen is measured with an electronic temperaturemeasuring device.When crystal formation is detected in thespecimen,the temperature is recorded and the specimen in thetest chamber is allowed to warm,while being continuouslystirred and monitored,until the crystals in the specimencompletely disappear.The temperature of the specimen whenthe last crystals disappear is recorded as the freezing point(automated method).5.Significance and Use5.1 The freezing point of an aviation fuel is an index of thelowest temperature of its utility for certain applications.Solidhydrocarbon crystals can restrict the flow of fuel in the fuelsystem of the aircraft.The temperature of the fuel in the aircrafttank normally decreases during flight depending on aircraftspeed,altitude,and flight duration.The freezing point of thefuel must always be lower than the minimum operational fueltemperature.5.2 Petroleum blending operations require precise measure-ment of the freezing point.5.3 This test method expresses results with a resolution of0.1C.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.07 on Flow Properties.Current edition approved May 10,2003.Published July 2003.Originallyapproved in 1996.Last previous edition approved in 1999 as D 590199.2Annual Book of ASTM Standards,Vol 05.01.3Annual Book of ASTM Standards,Vol 05.02.4Annual Book of ASTM Standards,Vol 14.03.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.5.4 This test method provides results that have been foundto be equivalent to the results from Test Method D 2386 onidentical samples.When the specification requires the use ofTest Method D 2386,do not substitute this test method or anyother method.6.Apparatus(see Annex A1)6.1 Automated Apparatus5The apparatus as described inAnnexA1 shall consist of a test chamber comprising a jacketedtest tube supported in a jacketed enclosure configuration that iscapable of cooling and heating the test specimen to thetemperatures required in the test.The apparatus shall have anitrogen purge collar as part of the closure assembly for the testchamber,which prevents moisture from combining with thetest specimen.The apparatus shall be capable of measuring thetemperature of the test specimen,continuously stirring the testspecimen at the prescribed rate,automatically cooling and thenheating the test specimen,monitori