ASTMD6749-2002

Designation:D 6749-02An American Nafional StandardNTERNATIONALStandard Test Method forPour Point of Petroleum Products (Automatic Air PressureMethod)1This standard is issued under the fixed designation D6749 the number immediately ollowing 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.INTRODUCTIONThis test method covers an altemative procedure for the determination of pour point of petroleumproducts using an automatic apparatus.1.ScopeIP15 Test Method for Pour Point of Petroleum Products41.1 This test method covers the determination of pour point3.Terminologyof petroleum products by an automatic apparatus that applies aslightly positive air pressure onto the specimen surface while3.1 Defnitions:the specimen is being cooled.3.1.1 pour point,n-in petroleum products,the lowest1.2 This test method is designed to cover the range oftemperature at which movement of the test specimen istemperatures from -57 to +51C;however,the range ofobserved under prescribed conditions of test.temperatures included in the (1998)interlaboratory test pro-3.2 Defnitions of Terms Specific to This Standard:gram only covered the temperature range from-51 to-11C.3.2.1 air pressure,na regulated slightly positive air pres-1.3 Test results from this test method can be determined atsure gently applied onto the specimen surface in the air-tighteither 1 or 3C testing intervals.test jar that causes upward movement of the specimen in the1.4 This test method is not intended for use with crude oils.communicating tube,which has one end inserted into the testspecimen and the other end at atmospheric pressure.NorE 1-The applicability of this test method on residual fuel samples3.2.2 no-flow point,nin petroleum products,the tempera-has not been verifi ed.For further information on the applicability,refer to13.4.ture of the test specimen at which a wax crystal structure of thetest specimen or viscosity increase,or both,impedes move-1.5 The values stated in SI units are regarded as standard.ment of the surface of the test specimen under the conditions of1.6 This standard does not purport to address all of thethe test.safety concerns,if any,associated with its use.It is the3.2.2.1 Discussion-The no-flow point occurs when,uponresponsibility of the user of this standard to establish appro-cooling,the formation of wax crystal structures or viscositypriate safety and health practices and determine the applica-increase,or both,has progressed to the point where the appliedbility of regulatory limitations prior to use.observation device no longer detects movement under the2.Referenced Documentsconditions of the test.The preceding observation temperature,at which flow of the test specimen is last observed,is the pour2.1 ASTM Standards:point.D 97 Test Method for Pour Point of Petroleum Pro