ASTM D5950-2002(2007) 923 Standard Test Method for Pour Point of Petroleum Products (Automatic Tilt Method)《石油产品的倾点(自动倾斜法)标准试验方法》.pdf

1、Designation: D 5950 02 (Reapproved 2007)An American National StandardStandard Test Method forPour Point of Petroleum Products (Automatic Tilt Method)1This standard is issued under the fixed designation D 5950; 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 (e) indicates an editorial change since the last revision or reapproval.INTRODUCTIONThis test method covers an alternative procedure for the determination of pour

3、 point of petroleumproducts using an automatic apparatus.1. Scope1.1 This test method covers the determination of pour pointof petroleum products by an automatic instrument that tilts thetest jar during cooling and detects movement of the surface ofthe test specimen with an optical device.1.2 This t

4、est method is designed to cover the range oftemperatures from 57 to +51C; however, the range oftemperatures included in the 1992 interlaboratory test programonly covered the temperature range from 39 to +6C, and therange of temperatures included in the 1998 interlaboratory testprogram was 51 to 11C.

5、 (See Section 13.)1.3 Test results from this test method can be determined at1 or 3C intervals.1.4 This test method is not intended for use with crude oils.NOTE 1The applicability of this test method on residual fuel sampleshas not been verified. For further information on applicability, refer to13.

6、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 concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish ap

7、pro-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 Petroleum ProductsD 4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD 4177 Practice for Auto

8、matic 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 petroleum products, the lowesttemperature at which movement of the test specimen isobserved under the prescribed c

9、onditions of this test method.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 conditions

10、 of the test.3.2.1.1 DiscussionThe no-flow point occurs when, uponcooling, the formation of wax crystal structures or the viscosityincrease, or both, has progressed to the point where the appliedobservation device no longer detects movement under theconditions of the test. The preceding observation

11、temperature,at which flow of the test specimen is last observed, is the pourpoint.3.2.2 tiltingtechnique of movement where the test jar in avertical position is moved towards a horizontal position toinduce specimen movement.3.2.2.1 DiscussionWhen the test jar is tilted and held in ahorizontal positi

12、on for 5 s without detection of specimenmovement, this is the no-flow point and the test is complete.4. Summary of Test Method4.1 After preliminary heating, the test specimen is insertedinto the automatic pour point apparatus. After starting theprogram, the specimen is cooled according to the coolin

13、g1This 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 Nov. 1, 2007. Published January 2008. Originallyapproved in 1996. Last previous edition approved i

14、n 2002 as D 595002.2For 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 page onthe ASTM website.3Available from Energy Institute, 61 New C

15、avendish St., London, WIG 7AR,U.K., http:/www.energyinst.org.uk.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.profile listed in Table 1 and examined at either 1 or 3Cintervals. The lowest temperature at which movement ofspecimen is

16、 detected, by the automatic equipment, is displayedas the pour point.NOTE 2If the automatic pour apparatuss preheat option is utilized,place the test specimen into the apparatus. After starting the program, theapparatus will automatically carry out the preliminary heating.5. Significance and Use5.1

17、The pour point of a petroleum product is an index of thelowest temperature of its utility for certain applications. Flowcharacteristics, like pour point, can be critical for the correctoperation of lubricating oil systems, fuel systems, and pipelineoperations.5.2 Petroleum blending operations requir

18、e precise measure-ment of the pour point.5.3 This test method can determine the pour point of the testspecimen with a resolution of 1.0C.5.4 Test results from this test method can be determined ateither 1 or 3C intervals.5.5 This test method yields a pour point in a format similarto Test Method D97/

19、IP 15 when the 3C interval results arereported.NOTE 3Since some users may wish to report their results in a formatsimilar to Test Method D97(in 3C intervals) the precisions were derivedfor the temperatures rounded to the 3C intervals. For statements on biasrelative to Test Method D97, see 13.3.5.6 T

20、his test method has better repeatability and reproduc-ibility relative to Test Method D97/IP 15 as measured in the1998 interlaboratory test program. (See Section 13.)6. Apparatus6.1 Optical Automatic Pour Point Apparatus4The auto-matic pour point apparatus described in this test methodconsists of a

21、microprocessor controller that is capable ofcontrolling one or more independent test cells. The apparatusshall include provisions for independently controlling thetemperature of each cell according to the specified coolingprofile, monitoring continuously the specimen temperature,and detecting any mo

22、vement of the specimen during tilting (seeFig. 1). The instrument shall be operated according to themanufacturers instructions.6.2 Temperature Probe, IEC 751 Class A: D T=6(0.15 + 0.002 |T|), capable of measurement from +70 down to80C. The temperature probe shall be in the center of the testjar and

23、the top of the platinum tip immersed 3 mm below thesurface of the oil.6.3 Test Jar, clear cylindrical glass, flat bottom, 34 60.1-mm outside diameter, 31 6 0.3-mm inside diameter, 120 60.5-mm height, thickness of the bottom 2.4-mm maximum. Itshall be marked with a line to indicate the sample height

24、54 60.5-mm above the inside bottom.6.4 Jacket, brass, cylindrical, flat bottom, 113 60.2-mm indepth, 45 +0, 0.1-mm inside diameter. It shall be cooledaccording to the cooling profile specified.6.5 Cooling Circulating Bath, equipped with a circulatingpump and capable of maintaining a temperature at l

25、east 10Cbelow the last required jacket temperature level (see Table 1and Fig. 2).6.6 Cork Disk,66 0.2 mm thick to fit loosely inside thejacket. Felt may be used but special attention must be paid toavoid moisture in the felt disk. The felt disk must be driedbefore each test.6.7 Cork Ring, to fit snu

26、gly around the outside of the test jarand loosely inside the test cell. Its purpose is to prevent the testjar from touching the cooling jacket.4The following apparatus have been found suitable for use in this test method:ISL models CPP 976 and CPP 972; available from ISL SA, BP 40, 14790 Verson,Fran

27、ce.TABLE 1 Jacket and Specimen Temperature Cooling ProfileSpecimen Temperature, C Jacket Temperature, C+27=ST+9 06 0.5+9=ST6 186 0.56=ST24 336 0.524=ST42 516 0.542=ST58 696 0.5FIG. 1 Optical Detection SystemD 5950 02 (2007)27. Reagents and Materials7.1 Methyl Alcohol, anhydrous, for use as cooling m

28、ediumin circulating bath.7.2 Cleaning Solvents, suitable for cleaning and drying thetest jar and test head, such as petroleum naphtha and hexane.(Warning: Flammable. Liquid causes eye burns. Vapor harm-ful. May be fatal or cause blindness if swallowed or inhaled.)8. Sampling8.1 Obtain a sample in ac

29、cordance with Practice D 4057 orPractice D 4177.8.2 Samples of very viscous materials can be warmed untilthey are reasonably fluid before they are transferred; however,no sample shall be heated more than is absolutely necessary.The sample shall not be heated and transferred into the testspecimen jar

30、 unless its temperature is 70C or lower.NOTE 4In the event the sample has been heated above this tempera-ture, allow the sample to cool until its temperature is at least 70C beforetransferring.9. Preparation of Apparatus9.1 Prepare the instrument for operation in accordance withthe manufacturers ins

31、tructions.9.2 Clean and dry the test head and test jar using suitablesolvents as prescribed by the manufacturer.9.3 Adjust the set-point of the recirculating cooler to theappropriate temperature to cool the jackets to the requiredtemperatures (see Table 1).NOTE 5For most applications the recirculati

32、ng cooler will be set at itslowest operating temperature.10. Calibration and Standardization10.1 Ensure that all of the manufacturers instructions forcalibrating, checking, and operating the apparatus are fol-lowed.10.1.1 A test head simulator, Part No. V02306, is used tocalibrate the equipment. The

33、 test head simulator uses precisionresistors in place of the PT 100 temperature probe to calibratethe jacket and specimen temperature electronics. Follow themanufacturers calibration instructions.10.2 A sample with a well documented pour point can beused to verify performance of the apparatus. Alter

34、natively, asample which has been extensively tested in a pour pointinterlaboratory study can be used.11. Procedure11.1 Pour the sample into the test specimen jar to the scribedmark. When necessary, heat the sample in a water bath or ovenuntil it is just sufficiently fluid to pour the sample into the

35、 testspecimen jar. Samples with an expected pour point above 36Cor samples which appear solid at room temperature can beheated above 45C, but should not be heated above 70C (seeNote 4).11.2 Subject the test specimen to the following preliminarytreatment or use the instruments automatic preheat optio

36、n.NOTE 6Residual 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.11.2.1 When the expected pour point (EP) is known to be#33C, heat the test specimen to 45C in a bath or ovenmaintained at 48C.11.2

37、.2 When the expected pour point (EP) is known to be33C, heat the test specimen to EP + 9C, or at least to 45Cbut no higher than 70C (see Note 4).11.3 Place a cork disk at the bottom of the jacket in therequired cell and fit a cork ring to the test jar. The cork ringshould be 25 6 3 mm above the bott

38、om of the test jar.11.4 Place the test jar in the selected test cell. Attach thedetector head according to the manufacturers instructions.11.5 Select the desired testing interval (1 or 3C).11.6 Enter the expected pour point (EP). If 3C testingintervals are chosen (11.5) you must enter an expected po

39、urpoint that is a multiple of 3C.11.7 Start the test in accordance with the manufacturersinstructions.11.8 At this point, the instrument shall monitor the testspecimen with the optical detector, adjusting the jacket tem-perature to the first temperature level (according to Table 1)and measuring the

40、specimen temperature. The instrument shallautomatically change the jacket temperature in accordancewith the specimen temperature (according toTable 1).The timeto move the jacket temperature from one level to the next lowerlevel shall not exceed 90 s. The instrument shall start tilting thespecimen (w

41、ithout removing it from the jacket) in the pre-scribed manner when the temperature of the test specimen is at9C higher than the expected pour point. If the specimen flowsduring the tilting movement, the no-flow point is not reachedand the jacket returns to the waiting vertical position for theFIG. 2

42、 Description of Pour Point Cell and Cooling Circulating BathD 5950 02 (2007)3next test. The test will continue until the jacket is in a completehorizontal position and the detector does not detect anymovement of the specimen for 5 s. This temperature, theno-flow point, plus 1 or 3C (depending on the

43、 test intervalselected) is the pour point of the oil (see Fig. 1). When the pourpoint is determined, the instrument shall display the pour pointresult and start to reheat the test specimen.11.9 If the instrument detects the no-flow point on the firsttilting cycle (EP + 9C), disregard the result and

44、start with 11.1using a higher expected pour point.11.10 Record the result as the pour point without anycorrection.NOTE 7Residual 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.12. Report12.1 Rep

45、ort the temperature recorded in 11.10 together withthe testing interval as pour point in accordance with TestMethod D 5950.13. Precision and Bias13.1 PrecisionThe precision of this test method as deter-mined by the statistical examination of the interlaboratory testresults is as follows:13.1.1 Pour

46、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 testmaterial, would in the long run, in the normal and correctoperation of this test method, excee

47、d the following, only in onecase in twenty.3.9C13.1.1.2 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,

48、 exceed the following, only in one case intwenty.6.1C13.1.2 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 r

49、un, in the normal and correctoperation of this test method, exceed the following, only in onecase in twenty.2.7C13.1.2.2 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.4.5C13.2 BiasSince there is no accepted reference materialsuitable for determining the b