1、Designation: D 6892 03An 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, in the case of rev
2、ision, 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. Scope1.1 This test method covers the determination of the pourpoint of petroleum products by an automatic i
3、nstrument 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 oftemperatures includ
4、ed 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 method on residua
5、l fuel sampleshas not been verified. For further information on the applicability, refer to13.4.1.5 The values stated in SI units are regarded as standard.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
6、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:D97 Test Method for Pour Point of Petroleum Products2D 4057 Practice for Manual Sampling of Petroleum andPetroleum Pro
7、ducts3D 4177 Practice for Automatic Sampling of Petroleum andPetroleum Products32.2 IP Standard:IP 15 Test Method for Pour Point of Petroleum Products43. Terminology3.1 Definitions:3.1.1 pour point, nin petroleum products, the lowesttemperature at which movement of the test specimen isobserved under
8、 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 orviscosity increase, or both, impedes movement of the surfaceof the test specimen under the condition
9、s 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 device no longer detects movement under theconditions of the test. The preceding observation tem
10、peratureat 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 specimen movement.3.2.2.1 DiscussionWhen the test jar is tilted and held in ahorizontal positio
11、n 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 pourpoint apparatus and initiation of the testing program, thespecimen is heated and then cooled ac
12、cording 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 jar is removed from the jacketed cooling chamber prior toeach examination. The lowest temperat
13、ure, when movement ofthe surface of the specimen is detected, is recorded as the pourpoint determined by this Test Method D 6892.5. 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
14、 pour point, can be critical for thecorrect operation of lubricating systems, fuel systems, andpipeline operations.5.2 Petroleum blending operations require precise measure-ment of the pour point.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants an
15、d is the direct responsibility of SubcommitteeD02.07 on Flow Properties.Current edition approved July 10, 2003. Published September 2003.2Annual Book of ASTM Standards, Vol 05.01.3Annual Book of ASTM Standards, Vol 05.02.4Available from Institute of Petroleum (IP), 61 New Cavendish St., London,WIG 7
16、AR, U.K.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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 format similarto Test Method D97or IP 15, when
17、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 D97or IP 15, see the research report.5.5 This
18、 test method has comparable repeatability and betterreproducibility relative to Test Method D97 or IP 15 asmeasured in the 1998 interlaboratory program.56. Apparatus6.1 Automatic Apparatus6The automatic pour point appa-ratus described in this test method (see Fig. 2) consists of amicroprocessor cont
19、rolled 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, while optically observing the surface of thespecimen for movement,
20、 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 diameter of 44.2 to 45.8 mm, and about115 mm in depth to accept the t
21、est 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 heightwith a wall thickness of 1.25 6 0.25 mm. The jar shall b
22、emarked 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 test jar and the topof the temperature sensing zone immersed bel
23、ow the surface ofthe specimen.6.4 Circulating BathRefrigeration unit, equipped with acirculating pump, capable of maintaining the liquid coolingmedium at a temperature at least 20C lower than the lowestexpected pour point to be measured. The circulating bath is5Supporting data have been filed at AST
24、M International Headquarters and maybe obtained by requesting Research Report RR: D02-1499.6The sole source of supply of the Herzog Model MP 852 or HCP 852 known tothe committee at this time is Walter Herzog, Lauda, Germany. If you are aware ofalternative suppliers, please provide this information t
25、o ASTM InternationalHeadquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee,1which you may attend.FIG. 1 Schematic of Cooling/Heating Block and Cooling Circulating BathFIG. 2 Picture of ApparatusD6892032connected to the automatic apparatus th
26、rough suitable meansfor supplying the liquid cooling medium.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 i
27、nhaled.)7.2 Cleaning SolventsSuitable for cleaning and drying 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 accord
28、ance with Practice D 4057 orPractice D 4177.8.2 Samples of 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 te
29、mperature is 70C or lower. When thesample is heated above 70C, 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
30、 settingsand the cooling/heating block change over temperature 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 o
31、f the sample.10. Calibration and Verification10.1 Ensure that 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 sam
32、ple which has been extensively tested in apour point cross- 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 un
33、tilit is just sufficiently fluid to pour into the test jar.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 inaccordan
34、ce with the manufacturers instructions.11.3 When the expected 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
35、of 45C.11.5 When the expected pour point is not known, preselecta 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 wh
36、enselecting starting temperatures above 45C. Samples which 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 you
37、r standard laboratory practice. Should the user wish toprovide 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 cool
38、ing/heating block shall be regulated inaccordance to the programmed 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
39、temperature level to the nextlower level shall not exceed 180 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
40、thenreturned to the block assembly. This complete operation 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
41、jar istilted horizontally for longer than 3 s and no movement 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 tiltingin
42、terval as the no-flow point.FIG. 3 Assembled ApparatusD6892033NOTE 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 cl
43、ean thetest jar and apparatus with suitable solvents 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
44、 pour point by thisTest Method D 6892.NOTE 5Some apparatus 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
45、 Point at 3C Testing Intervals:13.1.1.1 RepeatabilityThe 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 Temp
46、erature Cambient to 45 65 6 245 $ ST 27 15 6 127 $ 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 1.5D6892034material, would in the long run, in the normal and correctoperation of this test method, exceed the following, only in onecase in twenty:3.2C13
47、.1.1.2 ReproducibilityThe difference between 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:
48、3.6C13.1.2 Pour Point at 1C Testing Intervals: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 te
49、st 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 in the long run, in normal and correct operationof this test method, exceed the following, only in one case intwenty:2.3C13.2 BiasSince there is no accepted reference materialsuitable for determining the bias for the procedure in this testmethod, bias has not been
