1、Designation: D5772 15Designation: IP 445/09Standard Test Method forCloud Point of Petroleum Products (Linear Cooling RateMethod)1This standard is issued under the fixed designation D5772; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revis
2、ion, 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.INTRODUCTIONThis test method describes an alternative procedure for the determination of cloud point ofpetroleum
3、products of Test Method D2500/IP 219 using an automatic apparatus. The temperatureresults from this test method have been found to be equivalent to Test Method D2500/IP 219. Whenspecification requires Test Method D2500/IP 219, do not substitute this test method or any othermethod without obtaining c
4、omparative data and agreement from the specifier.1. Scope*1.1 This test method covers the description of the determi-nation of the cloud point of petroleum products and biodieselfuels that are transparent in layers 40 mm in thickness by anautomatic instrument using a linear cooling rate.1.2 This tes
5、t method covers the range of temperatures from60 C to 49 C with temperature resolution of 0.1 C,however, the range of temperatures included in the 1997interlaboratory cooperative test program only covered thetemperature range of 56 C to +34 C.1.3 The values stated in SI units are to be regarded asst
6、andard. No other units of measurement are included in thisstandard.1.4 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 ap
7、plica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D2500 Test Method for Cloud Point of Petroleum ProductsD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum Products2.2 Energ
8、y Institute Standard:IP 219 Test Method for Cloud Point of Petroleum Products33. Terminology3.1 Definitions:3.1.1 biodiesel, na fuel comprised of mono-alkyl esters oflong-chain fatty acids derived from vegetable oils or animalfats, designated B100.3.1.1.1 DiscussionBiodiesel is typically produced by
9、 areaction of vegetable oil or animal fat with an alcohol such asmethanol or ethanol in the presence of a catalyst to yield-mono-esters and glycerin. The fuel typically may contain up to14 different types of fatty acids that are chemically transformedinto fatty acid methyl esters (FAME).3.1.2 biodie
10、sel blend, na blend of biodiesel fuel withpetroleum-based diesel fuel designated BXX, where XX is thevolume percentage of biodiesel.3.1.3 cloud point, n in petroleum products and biodieselfuels, the temperature of a liquid specimen when the smallestobservable cluster of hydrocarbon crystals first oc
11、curs uponcooling under prescribed conditions.3.1.3.1 DiscussionThe cloud point occurs when the tem-perature of the specimen is low enough to cause hydrocarboncrystals to precipitate. In a homogeneous liquid, the cloud isalways noted first at the location in the specimen where the1This test method is
12、 under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.07 on Flow Properties.Current edition approved April 1, 2015. Published April 2015. Originallyapproved in 1995. Last previous edition approved in 2010
13、as D5772 10. DOI:10.1520/D5772-15.2For 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 Inst
14、itute, 61 New Cavendish St., London, WIG 7AR,U.K., http:/www.energyinst.org.uk.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1specimen temperature is the lowest. The cl
15、oud point is thetemperature at which the crystals first occur, regardless of theirlocation in the specimen, and not after extensive crystallizationhas taken place. The hydrocarbon crystals that precipitate atlower temperatures are typically, but not excluded to, straightchain hydrocarbons commonly c
16、alled “wax crystals.”3.1.3.2 DiscussionThe purpose of the cloud point methodis to detect the presence of the wax crystals in the specimen;however, trace amounts of water and inorganic compoundsmay also be present. The intent of the cloud point method is tocapture the temperature at which the liquid
17、fuel in the specimenbegins to change from a single liquid phase to a two-phasesystem containing solid and liquid. It is not the intent of thistest method to monitor the phase transition of the tracecomponents, such as water.3.2 Definitions of Terms Specific to This Standard:3.2.1 automatic cloud poi
18、nt, nthe temperature of a speci-men when the appearance of the cloud is determined under theconditions of this test method.3.2.1.1 DiscussionThe cloud point in this test method isdetermined by an automatic instrument using an optical devicefor detection of the crystal formation. The apparatus and th
19、econditions are different from those established for Test MethodD2500, although, according to interlaboratory examination, theresults have been determined to be equivalent to Test MethodD2500.3.2.2 linear cooling rate method, n in cloud point testmethods, test procedure using prescribed cooling rate
20、, speci-men receptacle, and optical system for detection of crystalformation.3.2.2.1 DiscussionThe prescribed cooling rate is de-scribed in 11.6; the specimen receptacle is described in AnnexA1, and the optical system for the detection of crystal forma-tion is described in Annex A1.3.2.3 D2500/IP 21
21、9 equivalent cloud point, nthe tempera-ture of a specimen, in integers, calculated by rounding theresults of this test method to the next lower integer.3.2.3.1 DiscussionThis test method produces results with0.1 C resolution. Should the user wish to provide results witha similar format to Test Metho
22、d D2500, then this calculationcan be performed. Some apparatus can perform this calculationautomatically.4. Summary of Test Method4.1 After insertion of the specimen into the apparatus andinitiation of the program, the prescribed specimen test cell(Annex A1) is heated and then linearly cooled at a s
23、pecifiedrate (11.6). The specimen is continuously monitored by anopposing optical light barrier (AnnexA1 and Fig.A1.3) for thecrystal structure formation. The temperature, when the crystal-lization of the wax in the specimen is detected by the opticalbarrier, is recorded with a resolution of 0.1 C.
24、The specimenis then heated to the original starting temperature.5. Significance and Use5.1 For petroleum products and diesel fuels, the cloud pointis an index of the lowest temperature of its utility for certainapplications. Wax crystals of sufficient quantity can plug filtersused in some fuel syste
25、ms.5.2 Petroleum blending operations require precise measure-ment of the cloud point.5.3 This test method can determine the temperature of thetest specimen at which wax crystals have formed sufficiently tobe observed as a cloud, with a resolution of 0.1 C.5.4 This test method provides results that w
26、hen rounded tothe next lower integer are equivalent to Test Method D2500.5.5 This test method is more precise than Test MethodD2500.6. Apparatus6.1 Automatic Apparatus4The automatic cloud point ap-paratus described in Annex A1 consists of a microprocessor-controlled measuring unit that is capable of
27、 heating, cooling,optically observing the appearance of the automatic cloudpoint, and recording the temperature of the specimen. Theapparatus shall be equipped with a digital display, cooling/heating block assembly, optical light barrier assembly, and atest cell of the approximate dimensions listed
28、in AnnexA1, andcontain a temperature measuring device.6.2 Beaker, glass or plastic (disposable) (50 mL), for con-taining the sample prior to introduction into the test cell.6.3 Circulating Bath, a refrigeration unit equipped with acirculating pump capable of maintaining a temperature at least20 C lo
29、wer than the lowest expected cloud point to bemeasured.7. Reagents and Materials7.1 Cleaning Solvents, suitable for cleaning and drying thetest cell, such as petroleum naphtha and acetone. (WarningFlammable. Liquid causes eye burns. Vapor is harmful. May befatal or cause blindness if swallowed or in
30、haled.)7.2 Methyl Alcohol, anhydrous, for use as cooling mediumin circulating bath.7.3 Lint-free filter paper may be used as a drying medium.8. Sampling8.1 Obtain a sample in accordance with Practices D4057 orD4177.8.2 Samples of very viscous materials may be warmed untilthey are reasonably fluid be
31、fore they are sampled. However, nosample should be heated more than absolutely necessary.8.3 The sample shall not be heated above 70 C. When thesample is heated above 70 C, allow the sample to cool below70 C before filtering or inserting into the apparatus.8.4 When moisture is present in the sample,
32、 remove themoisture by a method such as filtration through dry lint-free4The sole source of supply of the Herzog Model SC 815 and SC 819 known tothe committee at this time is Walter Herzog, Lauda, Germany. If you are aware ofalternative suppliers, please provide this information to ASTM Internationa
33、lHeadquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee,1which you may attend.D5772 152filter paper until the oil is perfectly clear. Make such filtrationat a temperature at least 14 C above the expected cloud point.NOTE 1Moisture will be no
34、ticed in the sample as a separate phase oras a haze throughout the entire sample. Generally, a slight haze will notinterfere with the detection of the wax cloud.9. Preparation of Apparatus9.1 Prepare the instrument for operation in accordance withthe manufacturers instructions.9.2 Clean and dry the
35、test cell using suitable solvents asprescribed by the manufacturer.9.3 Prepare the refrigerated circulating bath for operation inaccordance with the manufacturers instructions and allow it toattain a temperature at least 20 C lower than the expectedcloud point of the sample.10. Calibration and Stand
36、ardization10.1 Ensure that all of the manufacturers instructions forcalibrating, checking, and operating the apparatus are fol-lowed.10.2 A sample with a mutually agreed upon cloud point canbe used to verify performance of the apparatus.11. Procedure11.1 Pour at least 20 mL of the sample into the be
37、aker.When necessary, heat the sample in a water bath or oven untilit is just sufficiently fluid to pour into the beaker.11.2 Place the beaker under the entrance of the test cell andstart the test in accordance with the manufacturers instruc-tions.11.3 When the expected cloud point is known to be abo
38、ve25 C, preselect a starting temperature which is at least 14 Cabove the expected cloud point. The highest starting tempera-ture that can be programmed is 70 C.11.4 When the expected cloud point is known to be at orbelow 25 C, the test duration can be shortened by preselectinga starting temperature
39、which is at least 14 C above theexpected cloud point. The lowest starting temperature that canbe programmed is 20 C.11.5 When the expected cloud point is not known, preselecta starting temperature of 40 C. The apparatus automaticallyheats the test specimen to approximately 40 C when a startingtemper
40、ature is not selected. When the expected cloud point isnot known and the sample needs to be heated before transfer-ring into the test specimen beaker, preselect a starting tempera-ture of 70 C.11.6 A portion of the sample is drawn into the test cell.Initially, the specimen is heated to 40 C or to a
41、startingtemperature preselected by the operator between 20 C and70 C. The flow of the cooling fluid from the circulating bathis then regulated to maintain the rate of cooling of the specimenat 1 C 6 0.2 C per min (see Note 2). The specimen iscontinuously monitored by the optical light barrier and th
42、especimen temperature is continuously displayed. At the detec-tion of the automatic cloud point, the temperature the specimenattained, to within 0.1 C resolution, is held on the digitaldisplay until cleared by the operator. The specimen is thenheated to 40 C or to the preselected starting temperatur
43、e.NOTE 2Although the apparatus is capable of faster cooling rates of2 C or 3 C min, the interlaboratory program does not address theequivalency and precision of results using these cooling rates.11.7 Clean the test cell by flushing solvents through the celland then dry with clean air according to th
44、e manufacturersinstructions.NOTE 3Some apparatus is capable of automatic cleaning of the testcell and automatic sample changing.12. Report12.1 Report the temperature recorded in 11.6 as the auto-matic cloud point Test Method D5772.12.2 When specified, round the temperature recorded in11.6 to the nex
45、t lower integer and report as the D2500equivalent cloud point in accordance with Test Method D5772.13. Precision and Bias13.1 PrecisionThe precision of this test method as deter-mined by the statistical examination of the interlaboratory testresults5,6is as follows:13.1.1 RepeatabilityThe difference
46、 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 1.3 C only in one case intwenty.13.1.2 ReproducibilityThe differen
47、ce between two singleand independent test results obtained by different operatorsworking in different laboratories on identical test materialwould in the long run, in the normal and correct operation ofthis test method, exceed 3.3 C only in one case in twenty.13.1.3 The precision statements were der
48、ived from a 1997interlaboratory cooperative test program.6Participants ana-lyzed eleven sample sets, as blind duplicates, comprised ofvarious distillate fuels and lubricating oils with a temperaturerange from +34 C to 56 C. Five laboratories participatedwith the automatic apparatus and eight laborat
49、ories participatedwith the manual Test Method D2500/IP 219 test method.Information on the type of samples and their average cloudpoints are in the research report.513.2 BiasSince there is no accepted reference materialsuitable for determining the bias for the procedure in this testmethod, bias has not been determined.13.3 Relative BiasThe results of the interlaboratory pro-gram were examined for bias relative to Test Method D2500/IP219. Although statistically significant bias was observed, themagnitude was determine
