1、Designation:D674311(Reapproved 2015)Standard Test Method forThermal Stability of Organic Heat Transfer Fluids1This standard is issued under the fixed designation D6743;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.Scope1.1 This test method covers the determination of the thermalstability of unused organic heat transfer fluids.The procedureis applica
3、ble to fluids used for the transfer of heat at tempera-tures both above and below their boiling point(refers to normalboiling point throughout the text unless otherwise stated).It isapplicable to fluids with maximum bulk operating temperaturebetween 260 C(500 F)and 454 C(850 F).The procedureshall no
4、t be used to test a fluid above its critical temperature.Inthis test method,the volatile decomposition products are incontinuous contact with the fluid during the test.This testmethod will not measure the thermal stability threshold(thetemperature at which volatile oil fragments begin to form),butin
5、stead will indicate bulk fragmentation occurring for a speci-fied temperature and testing period.Because potential decom-position and generation of high pressure gas may occur attemperatures above 260 C(500 F),do not use this testmethod for aqueous fluids or other fluids which generatehigh-pressure
6、gas at these temperatures.1.2 DIN Norm 51528 covers a test method that is similar tothis test method.1.3 The applicability of this test method to siloxane-basedheat transfer fluids has not been determined.1.4 The values stated in SI units are to be regarded asstandard.The values given in parentheses
7、 are for informationonly.1.5 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
8、to use.For specificwarning statements,see 7.2,8.8,8.9,and 8.10.2.Referenced Documents2.1 ASTM Standards:2D2887 Test Method for Boiling Range Distribution of Pe-troleum Fractions by Gas ChromatographyD4175 Terminology Relating to Petroleum,PetroleumProducts,and LubricantsE691 Practice for Conducting
9、an Interlaboratory Study toDetermine the Precision of a Test Method2.2 DIN Norms:351528 Determination of the Thermal Stability of UnusedHeat Transfer Fluids3.Terminology3.1 Definitions:3.1.1 thermal stability,nthe resistance to permanentchanges in properties caused solely by heat.D41753.2 Definition
10、s of Terms Specific to This Standard:3.2.1 decomposition products that cannot be vaporized,nmaterials from the thermally stressed heat transfer fluid,from which those fractions that can be vaporized are removedby distillation procedures,that are quantitatively determined asresidues in a bulb tube di
11、stillation apparatus.3.2.2 fluid within the unstressed fluid boiling range,nanyfluid components with boiling point between the initial boilingpoint and final boiling point of the unstressed fluid.3.2.3 gaseous decomposition products,nmaterials withboiling points below room temperature,at normal pres
12、sure,such as hydrogen and methane,that escape upon opening thetest cell and that can be determined by measuring the massimmediately thereafter.3.2.4 high boiling components,nmaterials from the ther-mally stressed heat transfer fluid,with boiling points above thefinal boiling point of the unstressed
13、heat transfer fluid,but1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.L0.06 on Non-Lubricating Process Fluids.Current edition approved July 1,2015.Published July 2015.Originally ap
14、provedin 2001.Last previous edition approved in 2011 as D6743 11.DOI:10.1520/D6743-11R15.2For 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 p
15、age onthe ASTM website.3Available from Deutsches Institut fur Normung e.V.(DIN),Burggrafenstrasse 6,10787 Berlin,Germany,http:/www.din.de.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 which can still be separated by distillation from th
16、e heattransfer fluid by means of classical separation procedures.3.2.5 low boiling components,nmaterials from the ther-mally stressed heat transfer fluid,with boiling points below theinitial boiling point of the unstressed heat transfer fluid.3.2.6 mass percentage of high boiling components,nthepercentage of thermally stressed heat transfer fluid with aboiling point above the final boiling point of the unstressedfluid.3.2.7 mass percentage of low boiling components,nthepercentage of thermally st