1、Designation: D 6892 03 (Reapproved 2008)An American National StandardStandard Test Method forPour Point of Petroleum Products (Robotic Tilt Method)1This standard is issued under the fixed designation D 6892; the number immediately following the designation indicates the year oforiginal adoption or,
2、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 pourpoint of petroleum products
3、by an automatic instrument thattilts the test jar to detect movement of the surface of the testspecimen with an optical device, after being removed from aregulated, stepped-bath cooling jacket.1.2 This test method is designed to cover the range oftemperatures from 57 to +51C; however, the range ofte
4、mperatures included in the 1998 interlaboratory test programonly covered the temperature range from 51 to 11C.1.3 Test results from this test method can be determined ateither 1 or 3C testing intervals.1.4 This test method is not intended for use with crude oils.NOTE 1The applicability of this test
5、method on residual fuel sampleshas not been verified. For further information on the applicability, refer to13.4.1.5 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
6、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.2. Referenced Documents2.1 ASTM Standards:2D97 Test Method for Pour Point of P
7、etroleum ProductsD 4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD 4177 Practice for Automatic Sampling of Petroleum andPetroleum Products2.2 Energy Institute Standard:3IP 15 Test Method for Pour Point of Petroleum Products3. Terminology3.1 Definitions:3.1.1 pour point, nin pet
8、roleum products, the lowesttemperature at which movement of the test specimen isobserved under prescribed conditions of test.3.2 Definitions of Terms Specific to This Standard:3.2.1 no-flow point, nin petroleum products, the tempera-ture of the test specimen at which a wax crystal structure orviscos
9、ity increase, or both, impedes movement of the surfaceof the test specimen under the conditions of the test.3.2.1.1 DiscussionThe no-flow point occurs when, uponcooling, the formation of wax crystal structures or viscosityincrease, or both, has progressed to the point where the appliedobservation de
10、vice no longer detects movement under theconditions of the test. The preceding observation temperatureat which flow of the test specimen is last observed is the pourpoint.3.2.2 tilting, vttechnique of movement where the test jarin a vertical position is moved towards a horizontal position toinduce s
11、pecimen movement.3.2.2.1 DiscussionWhen the test jar is tilted and held in ahorizontal position for 5 s without detection of movement ofthe surface of the specimen, this is the no-flow point and thetest is complete.4. Summary of Test Method4.1 After insertion of the specimen into the automatic pourp
12、oint apparatus and initiation of the testing program, thespecimen is heated and then cooled according to a prescribedprofile. The specimen surface is examined periodically formovement using an optical camera system mounted on top ofthe specimen test jar, while tilting the specimen test jar. Thetest
13、jar is removed from the jacketed cooling chamber prior toeach examination. The lowest temperature, when movement ofthe surface of the specimen is detected, is recorded as the pourpoint determined by this Test Method D 6892.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum
14、 Products and Lubricants and is the direct responsibility of SubcommitteeD02.07 on Flow Properties.Current edition approved Dec. 15, 2008. Published February 2009.Originallyapproved in 2003. Last previous edition approved in 2003 as D 689203.2For 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.3Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR,U.K., http:/www.energyinst.org.uk.1Copyright AS
16、TM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Significance and Use5.1 The pour point of a petroleum product is an index of thelowest temperature of its utility for certain applications. Flowcharacteristics, such as pour point, can be critica
17、l for thecorrect operation of lubricating systems, fuel systems, andpipeline operations.5.2 Petroleum blending operations require precise measure-ment of the pour point.5.3 Test results from this test method can be determined ateither 1 or 3C intervals.5.4 This test method yields a pour point in a f
18、ormat similarto Test Method D97or IP 15, when the 3C interval results arereported.NOTE 2Since some users may wish to report their results in a formatsimilar to Test Method D97or IP 15 (in 3C intervals) the precision datawere derived for the 3C intervals. For statements on bias relative to TestMethod
19、 D97or IP 15, see the research report.5.5 This test method has comparable repeatability and betterreproducibility relative to Test Method D97 or IP 15 asmeasured in the 1998 interlaboratory program (see Section 13).6. Apparatus6.1 Automatic Apparatus4The automatic pour point appa-ratus described in
20、this test method (see Fig. 2) consists of amicroprocessor controlled measuring unit that is capable ofheating the specimen to programmed temperatures, cooling thespecimen according to programmed cooling profiles, mechani-cally manipulating the test jar according to the programmedtest procedure, whil
21、e optically observing the surface of thespecimen for movement, using a camera system mounted ontop of the specimen test jar and recording the temperature ofthe specimen. The apparatus shall be equipped with a userinterface, cooling/heating block assembly with cylindricaljacket with an inside diamete
22、r of 44.2 to 45.8 mm, and about115 mm in depth to accept the test jar) robotic mechanisms forlifting, tilting, replacing the test jar, optical camera system, anda temperature measuring device.6.2 Test JarClear, cylindrical glass, flat bottom (dark-ened), 31.5 6 0.5 mm inside diameter and 120 6 2 mm
23、heightwith a wall thickness of 1.25 6 0.25 mm. The jar shall bemarked with a line to indicate sample filling height correspond-ing to 45 6 0.5 mL.6.3 Temperature ProbeCapable of measurement from +70to 80C with a resolution of 0.1C. The temperature probeshall be suspended in the center axis of the te
24、st jar and the topof the temperature sensing zone immersed below the surface ofthe specimen.6.4 Circulating BathRefrigeration unit, equipped with acirculating pump, capable of maintaining the liquid cooling4The sole source of supply of the Herzog Model MP 852 or HCP 852 known tothe committee at this
25、 time is Walter Herzog, Lauda, Germany. If you are aware ofalternative suppliers, please provide this information to ASTM InternationalHeadquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee,1which you may attend.FIG. 1 Schematic of Cooling/H
26、eating Block and Cooling Circulating BathFIG. 2 Picture of ApparatusD 6892 03 (2008)2medium at a temperature at least 20C lower than the lowestexpected pour point to be measured. The circulating bath isconnected to the automatic apparatus through suitable meansfor supplying the liquid cooling medium
27、.7. Reagents and Materials7.1 Bath Cooling MediumSuitable for use in the circulat-ing bath (an example is methyl alcohol-anhydrous).(WarningFlammable. Liquid causes eye burns. Vapor harm-ful. May be fatal or cause blindness if swallowed or inhaled.)7.2 Cleaning SolventsSuitable for cleaning and dryi
28、ng thetest jar and temperature measuring device, such as; petroleumnaphtha or acetone. (WarningFlammable. Liquid causes eyeburns. Vapor harmful. May be fatal or cause blindness ifswallowed or inhaled.)8. Sampling8.1 Obtain a sample in accordance with Practice D 4057 orPractice D 4177.8.2 Samples of
29、very viscous materials may be warmed untilthey are reasonably fluid before they are tested. However, nosample shall be heated more than is absolutely necessary.8.3 The sample shall not be heated and transferred into thetest jar unless its temperature is 70C or lower. When thesample is heated above 7
30、0C, allow the sample to cool below70C before transferring into the test jar.9. Preparation of Apparatus9.1 Prepare the instrument for operation in accordance withthe manufacturers instructions.9.2 Select the cooling/heating block temperature settingsand the cooling/heating block change over temperat
31、ure set-tings, in accordance with Table 1.9.3 Clean and dry the test jar using suitable solvents.9.4 Prepare the refrigerated circulating bath for operationand allow it to attain a temperature at least 20C lower than theexpected pour point of the sample.10. Calibration and Verification10.1 Ensure th
32、at all of the manufacturers instructions forcalibrating, checking, and operating the apparatus are fol-lowed.10.2 A sample with a well-documented pour point can beused to verify the performance of the automatic apparatus.Alternatively, a sample which has been extensively tested in apour point cross-
33、 check program can be used. Such verificationmaterials can also be prepared from intra-company crosschecks.11. Procedure11.1 Fill the test jar up to the marked line with the specimen.When necessary, heat the sample in a water bath or oven untilit is just sufficiently fluid to pour into the test jar.
34、NOTE 3Residual fuels have been known to be sensitive to thermalhistory. In the case where a residual fuel sample is tested, refer to TestMethod D97for sample treatment.11.2 Insert the test jar into the apparatus and start the test inaccordance with the manufacturers instructions.11.3 When the expect
35、ed pour point is known to be above33C, preselect a starting temperature which is at least 9Cabove the expected pour point, but to at least 45C.11.4 When the expected pour point is known to be at orbelow 33C, preselect a starting temperature of 45C.11.5 When the expected pour point is not known, pres
36、electa starting temperature of 45C. When the expected pour pointis not known and the sample must be heated to allow transferinto the test jar, preselect a starting temperature correspondingto the preheat temperature. (WarningExercise care whenselecting starting temperatures above 45C. Samples which
37、arefluid at ambient room temperature can also have a lowtemperature flash point. Use higher start temperatures only onsamples known to be solid near ambient room temperature.)11.6 Preselect the testing interval of 1 or 3C as determinedby your standard laboratory practice. Should the user wish toprov
38、ide results with a similar format to Test Method D97orIP 15, then testing at a 3C interval shall be selected.11.7 Once the operation of the apparatus is initiated, thespecimen is heated to the temperature preselected by theoperator. The cooling/heating block shall be regulated inaccordance to the pr
39、ogrammed temperature settings obtainedfrom Table 1. The instrument shall automatically change theblock temperature in accordance with the specimen tempera-ture (according to Table 1). The time required to move thejacket temperature from one temperature level to the nextlower level shall not exceed 1
40、80 s.11.8 Beginning at the preselected start testing temperature,the test jar shall be lifted out of the block assembly, tiltedtoward a horizontal position, until movement of the surface ofthe specimen is detected by the optical system, and thenreturned to the block assembly. This complete operation
41、 shalltake no longer than 3 s when specimen surface movement isobserved. This operation shall be repeated at each subsequentlower temperature interval that has been preselected by theoperator. The operations shall be repeated until the test jar istilted horizontally for longer than 3 s and no moveme
42、nt of thesurface of the specimen is detected for a maximum of 5 s. Ifmovement is detected between 3 to 5 s, the test jar is returnedto the block assembly and the operations continued.11.9 Record the temperature measured at the last tiltinginterval as the no-flow point.FIG. 3 Assembled ApparatusD 689
43、2 03 (2008)3NOTE 4Some apparatus are capable of returning the test jar to theblock assembly and the specimen can be reheated to a previouslyprogrammed temperature to facilitate disposal and cleaning.11.10 Remove the test jar from the apparatus and clean thetest jar and apparatus with suitable solven
44、ts and then dry withclean air according to the manufacturers instructions.12. Report12.1 Increase the temperature recorded in 11.9 by a tem-perature amount equal to the testing interval used, and reportthe result including the testing interval as the pour point by thisTest Method D 6892.NOTE 5Some a
45、pparatus are capable of automatically calculating andreporting these temperatures.13. Precision and Bias13.1 PrecisionThe precision of this test method as deter-mined by statistical examination of interlaboratory test resultsis as follows:13.1.1 Pour Point at 3C Testing Intervals:13.1.1.1 Repeatabil
46、ityThe difference between successivetest results, obtained by the same operator using the sameapparatus under constant operating conditions on identical testFIG. 4 Interface PanelTABLE 1 Block and Specimen TemperatureSpecimen Temperature C Block Temperature Cambient to 45 65 6 245 $ ST 27 15 6 127 $
47、 ST 9 0 6 19 $ ST 6 18 6 16 $ ST 24 33 6 124 $ ST 42 51 6 1.542 $ ST 60 69 6 1.560 $ ST 78 87 6 1.5D 6892 03 (2008)4material, would in the long run, in the normal and correctoperation of this test method, exceed the following, only in onecase in twenty:3.2C13.1.1.2 ReproducibilityThe difference betw
48、een twosingle and independent test results, obtained by differentoperators working in different laboratories on identical testmaterial, would in the long run, in normal and correct operationof this test method, exceed the following, only in one case intwenty:3.6C13.1.2 Pour Point at 1C Testing Inter
49、vals:13.1.2.1 RepeatabilityThe difference between successivetest results, obtained by the same operator using the sameapparatus under constant operating conditions on identical testmaterial, would in the long run, in the normal and correctoperation of this test method, exceed the following, only in onecase in twenty:1.8C13.1.2.2 ReproducibilityThe difference between twosingle and independent test results, obtained by differentoperators working in different laboratories on identical testmaterial, would
