1、Designation: D5771 15Designation: IP 44409Standard Test Method forCloud Point of Petroleum Products (Optical DetectionStepped Cooling Method)1This standard is issued under the fixed designation D5771; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、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.INTRODUCTIONThis test method describes an alternative procedure for the determination of cloud point
3、 ofpetroleum products Test Method D2500/IP 219 using an automatic apparatus. The temperature resultsfrom 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 o
4、btaining comparative 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 an optical device.1.2 T
5、his test method covers the range of temperaturesfrom 60 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 regar
6、ded asstandard. 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 determin
7、e the applica-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 ProductsD
8、6708 Practice for Statistical Assessment and Improvementof Expected Agreement Between Two Test Methods thatPurport to Measure the Same Property of a Material2.2 Energy Institute Standard:3IP 219 Test Method for Cloud Point of Petroleum Products32.3 Other Standard:4IEC 751 Industrial Platinum Resista
9、nce Thermometer Sen-sors3. Terminology3.1 Definitions:3.1.1 biodiesel, nfuel comprised of mono-alkyl esters oflong chain fatty acids derived from vegetable oils or animalfats, designated B 100.3.1.1.1 DiscussionBiodiesel is typically produced by areaction of vegetable oil or animal fat with an alcoh
10、ol such asmethanol or ethanol in the presence of a catalyst to yieldmono-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 biodiesel blend, na blend of biodiesel fuel withpetroleum-base
11、d diesel fuel designated BXX, where XX is thevolume % of biodiesel.1This test method is 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. Pu
12、blished April 2015. Originallyapproved in 1995. Last previous edition approved in 2012 as D5771 12. DOI:10.1520/D5771-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refe
13、r 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.4Available from International Electrotechnical Commission (IEC), 3 rue deVaremb, Case postale 131, CH-1211, Geneva 20, Switzerland, ht
14、tp:/www.iec.ch.*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 States13.1.3 cloud point, n in petroleum products and biodieselfuels, the temperature of a liquid specimen when t
15、he smallestobservable cluster of hydrocarbon crystals first occurs 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
16、 at the location in the specimen where thespecimen temperature is the lowest. The cloud 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 te
17、mperatures are typically, but not excluded to, straightchain hydrocarbons commonly called “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 be present. The int
18、ent of the cloud point method is tocapture the temperature at which the liquids in the specimenbegin 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.
19、2 Definitions of Terms Specific to This Standard:3.2.1 automatic cloud point, 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
20、optical devicefor detection of the crystal formation. The apparatus and theconditions 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 optical detection stepped coo
21、ling method, nin cloudpoint test methods, test procedure using prescribed coolingrate, specimen receptacle, and optical system for detection ofcrystal formation.3.2.2.1 DiscussionThe prescribed cooling rate is de-scribed in 4.1; the specimen receptacle is described in Section6, and the optical syste
22、m for the detection of crystal formationis described in Section 6.3.2.3 D2500/IP 219 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 res
23、olution. Should the user wish to provide results witha similar format to Test Method D2500, then this calculationcan be performed. Some apparatus can perform this calculationautomatically.4. Summary of Test Method4.1 After insertion of the prescribed test jar (6.3) containingthe specimen into the ap
24、paratus, and the initiation of theprogram, the specimen is cooled incrementally according to thecooling profile listed in Table 1. The specimen is continuouslymonitored by a reflective optical system (6.1 and Fig. 1) for theformation of a crystalline structure. When the crystallization ofthe wax in
25、the specimen is detected by the optical system, thetemperature is recorded to within 0.1 C resolution. Thespecimen is then heated to facilitate the start of the next test.5. Significance and Use5.1 For petroleum products and biodiesel fuels, the cloudpoint is an index of the lowest temperature of th
26、eir utility forcertain applications. Wax crystals of sufficient quantity canplug filters used in some fuel systems.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 forme
27、d sufficiently tobe observed as a cloud with a resolution of 0.1C.5.4 This test method provides results that, when rounded tothe next lower integer, are equivalent to Test Method D2500.Refer to 12.2.5.5 This test method is more precise than Test MethodD2500.NOTE 1According to interlaboratory examina
28、tion, the reproducibilityof this test method has been found to be more precise than Test MethodD2500.6. Apparatus6.1 Optical Cloud Point Apparatus5The automated cloudpoint apparatus (see Fig. 2) described in this test methodconsists of a microprocessor controller that is capable ofcontrolling one or
29、 more independent test cells. The apparatusshall include provisions for independently controlling thetemperature of each cell according to the specified coolingprofile, continuously monitoring the specimen temperature,detecting the appearance of the cloud point at the bottom of thetest jar without r
30、emoving it from the jacket, and displaying the0.1 C or 1.0 C result (see Fig. 1 and Fig. 3).6.2 Temperature Probe, IEC 751 Class A: T=6(0.15 +0.002 |T|), capable of measurement from 50 C to +80 C.The temperature probe shall be in contact with the bottom ofthe test jar.6.3 Test Jar, clear cylindrical
31、 glass, mirrored flat bottom,34 mm 6 0.5 mm outside diameter, 1.4 mm 6 0.15 mm wallthickness, 120 mm 6 0.5 mm height, thickness of the bottom2.0 mm 6 0.5 mm, marked with a line to indicate the sampleheight 54 mm 6 0.5 mm above the inside bottom.6.4 Jacket, brass, cylindrical, flat bottom, 113 mm 60.
32、2 mm in depth, 45 mm 6 0.1 mm inside diameter. It must becooled according to the cooling profile specified.6.5 Cooling System, either an external system equipped witha circulating pump and capable of maintaining a temperature atleast 10 C below the last required jacket temperature level5The sole sou
33、rce of supply of the ISL Model CPP97-6 and CPP97-2 andCPP-5Gs known to the committee at this time is ISL SA, BP 40, 14790 Verson,France. If you are aware of alternative suppliers, please provide this information toASTM International Headquarters. Your comments will receive careful consider-ation at
34、a meeting of the responsible technical committee,1which you may attend.D5771 152(see Table 1 and Fig. 3), or an internal system capable ofmaintaining the required jacket temperatures (see Table 1 andFig. 3).6.6 Cork Disk, 6mm6 0.2 mm thick, to fit loosely insidethe jacket. Felt may be used but speci
35、al attention must be givento the potential for moisture in the felt disk. The felt must bedried before each test.6.7 Cork Ring, to fit snugly around the outside of the test jarand loosely inside the sample cell. Its purpose is to prevent thetest jar from touching the jacket.TABLE 1 Jacket and Specim
36、en Cooling TemperaturesSpecimen Temperature, C Jacket Temperature, CST+10 00.5+10$ ST 7 17.2 0.57 $ ST 24 34.2 0.524 $ ST 41 51.2 0.541 $ ST 58 68.2 0.558 $ ST 75 85.2 0.5FIG. 1 Test Jar and Detection SystemD5771 1537. Reagents and Materials7.1 Cleaning Solvents, suitable for cleaning and drying the
37、test cell, such as petroleum naphtha and hexane.7.2 Methyl Alcohol, Anhydrous, for use as cooling mediumin circulating bath cooling system, when used.FIG. 2 Automated Cloud Point ApparatusD5771 1547.3 Sodium SulfateA reagent grade of anhydrous sodiumsulfate should be used when required. (WarningFlam
38、mable.Liquid causes eye burns. Vapor harmful. May be fatal or causeblindness if swallowed or inhaled.)7.4 Lint-free filter paper may be used as a drying medium.8. Sampling8.1 Obtain a sample in accordance with Practices D4057 orby D4177.8.2 Samples of very viscous materials may be warmed untilthey a
39、re reasonably fluid before they are sampled. However, nosample should be heated more than is absolutely necessary.8.3 The sample shall not be heated above 70 C. If 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
40、 present in the sample, remove themoisture by a method, such as filtration through dry lint-freefilter paper, until the oil is perfectly clear, but make suchfiltration at a temperature at least 14 C above the expectedcloud point.NOTE 2A wax cloud or haze is always noted at the bottom of the testjar
41、where the temperature is lowest. A slight haze throughout the entirespecimen, which slowly becomes more apparent as the temperature islowered, is usually due to water in the specimen. Generally this water hazewill not interfere with the determination of the wax cloud point. In mostcases of interfere
42、nce, filtration through dry lint-free filter papers such asdescribed in 11.2 is sufficient.8.5 For diesel fuels, if the haze is very dense, a fresh portionof sample must be dried by shaking 100 mL with5gofanhydrous sodium sulfate for at least 5 min and then filteringthrough dry lint-free filter pape
43、r. Given sufficient contact time,this procedure will remove or sufficiently reduce the water hazeso that the wax cloud can be readily discerned. Drying andfiltering should always be done at a temperature at least 14 Cabove the approximate cloud point, but otherwise not in excessof 49 C.9. Preparatio
44、n of Apparatus9.1 Prepare the instrument for operation in accordance withthe manufacturers instructions.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 cooling system, whennecessary, to the appropriate temperature
45、to cool the jacket tothe required temperature (see Table 1).10. Calibration and Standardization10.1 Ensure that all of the manufacturers instructions forcalibrating, checking, and operating the apparatus are fol-lowed.10.1.1 Atest head simulator with a known resistance is usedto calibrate the equipm
46、ent. Follow the manufacturers calibra-tion instructions.NOTE 3A test head simulator may be obtained from the apparatussupplier which can assist in verification of temperature measurement.10.2 A sample with a mutually agreed upon cloud pointsuch as a sample from a interlaboratory test program can beu
47、sed to verify performance of the apparatus.11. Procedure11.1 Set the temperature unit on the apparatus to 1 C or to0.1 C.NOTE 4The temperature unit, in common laboratory practice, is 1 C.If a higher resolution is desired, 0.1 C can be selected.11.2 Using a water bath or oven, bring the sample to bet
48、ested to a temperature at least 14 C above the expected cloudpoint. When moisture is present in the sample, remove themoisture present by a method, such as filtration through drylint-free filter paper, until the sample is perfectly clear, butmake such filtration at a temperature of at least 14 C abo
49、ve theapproximate cloud point but otherwise not in excess of 70 C.11.3 Pour the clear sample into the test jar to the level mark.11.4 Place a cork disk at the bottom of the jacket in theappropriate cell and fit a cork ring around the test jar. Use thecork placement guide, if necessary, for the final adjustment.The cork ring must be 25 mm 6 3.0 mm above the bottom ofthe test jar.NOTE 5A cork placement guide may be obtained from the apparatussupplier which can assist in proper placement of the
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