1、Designation: D5773 10Designation: 446/99Standard Test Method forCloud Point of Petroleum Products (Constant Cooling RateMethod)1This standard is issued under the fixed designation D5773; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi
2、on, 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 p
3、roducts 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 obtaining compa
4、rative data and agreement from the specifier.1. Scope*1.1 This test method covers the determination of the cloudpoint of petroleum products and biodiesel fuels that aretransparent in layers 40 mm in thickness by an automaticinstrument using a constant cooling rate.1.2 This test method covers the ran
5、ge of temperatures from60 to +49C with temperature resolution of 0.1C, however,the range of temperatures included in the 1997 interlaboratorycooperative test program only covered the temperature range of56 to +34C.1.3 The values stated in SI units are to be regarded as thestandard. The values given
6、in parentheses are for informationonly.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 applica-bility of regulatory l
7、imitations 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 Energy Institute Standard:3IP 219
8、 Test Method for Cloud Point of Petroleum Products3. 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 areaction of vegetable oil
9、or animal fat with an alcohol 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 biodie
10、sel fuel withpetroleum-based diesel fuel designated BXX, where XX is thevolume percentage of biodiesel.3.1.3 cloud point, nin petroleum products and biodieselfuels, the temperature of a liquid specimen when the smallestobservable cluster of hydrocarbon crystals first occurs uponcooling under prescri
11、bed 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 under the jurisdiction of AST
12、M Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.07 on Flow Properties.Current edition approved May 1, 2010. Published August 2010. Originallyapproved in 1995. Last previous edition approved in 2007 as D577307. DOI:10.1520/D5773-10.2For referenc
13、ed 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 Cavendish St., London, WIG 7AR,U.
14、K., http:/www.energyinst.org.uk.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.specimen temperature is the lowest. The cloud point is thetemperature at which the crys
15、tals 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 called “wax crystals.”3.1.3.2 DiscussionThe pu
16、rpose of the cloud point is tomeasure the wax crystals in the specimen; however, traceamounts of water and inorganic compounds may also bepresent.The intent of the cloud point measurement is to capturethe temperature at which the liquid fuel in the specimen beginsto change from a single liquid phase
17、 to a two-phase systemcontaining solid and liquid. It is not the intent of this testmethod to monitor the phase transition of the trace componentssuch as water.3.2 Definitions of Terms Specific to This Standard:3.2.1 automatic cloud point, nthe temperature of a speci-men, when the appearance of the
18、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 theconditions are different from those established for Test Metho
19、dD2500, although according to interlaboratory examination, theresults have been determined to be equivalent to Test MethodD2500.3.2.2 constant cooling rate method, nin cloud point testmethods, test procedure using prescribed cooling rate, speci-men receptacle, and optical system for detection of cry
20、stalformation.3.2.2.1 DiscussionThe prescribed cooling rate is de-scribed in 4.1; the specimen receptacle is described in AnnexA1; and the optical system for the detection of crystalformation is described in Annex A1.3.2.3 Peltier device, na solid state thermoelectric deviceconstructed with dissimil
21、ar semiconductor materials and con-figured in such a way that it will transfer heat to or away froma test specimen dependent on the direction of electric currentapplied to the device.3.2.4 D2500/IP 219 equivalent cloud point, nthe tempera-ture of a specimen, in integers, calculated by rounding there
22、sults of this test method to the next lower integer.3.2.4.1 DiscussionThis test method produces results with0.1C resolution. Should the user wish to provide results witha similar format to Test Method D2500, then this calculationcan be performed. Some apparatus can perform this calculationautomatica
23、lly.4. Summary of Test Method4.1 A prescribed specimen (11.5) is cooled by a Peltierdevice (A1.1) at a constant rate of 1.5 6 0.1C/min whilecontinuously being illuminated by a light source (A1.1.4). Thespecimen is continuously monitored by an array of opticaldetectors (A1.1.5, Fig.A1.1) for the firs
24、t appearance of a cloudof wax crystals. The detectors are sufficient in number toensure that any solid phase hydrocarbon crystals that may formare detected. The temperature at which the appearance of acloud of wax crystals is first detected in the specimen isrecorded to 0.1C resolution. When the rec
25、orded temperature isrounded to the next lower integer temperature, it is designatedas the D2500/IP 219 equivalent cloud point per Test MethodD5773.5. Significance and Use5.1 The cloud point of petroleum products and biodieselfuels is an index of the lowest temperature of their utility forcertain app
26、lications. Wax crystals of sufficient quantity canplug filters used in some fuel systems.5.2 Petroleum blending operations require a precise mea-surement of the cloud point.5.3 This test method can determine the temperature of thetest specimen at which wax crystals have formed sufficiently tobe obse
27、rved as a cloud with a resolution of 0.1C.5.4 This test method provides results that are equivalent toTest Method D2500.NOTE 1This is based on the Test Method D2500 equivalent cloudpoint in which the 0.1C result is rounded to the next lower integer.5.5 This test method determines the cloud point in
28、a shorterperiod of time than Test Method D2500.NOTE 2In cases of samples with cloud points near ambient tempera-tures, time savings may not be realized.5.6 This test method eliminates most of the operator timerequired of Test Method D2500.5.7 This test method does not require the use of a mechani-ca
29、l refrigeration apparatus.NOTE 3In certain cases of high ambient temperature, a source ofcooling water may be required to measure low temperature cloud points(see 7.1).6. Apparatus6.1 Automatic Apparatus4The automatic cloud point ap-paratus described in this test method consists of a test chambercon
30、trolled by a microprocessor that is capable of controllingthe heating and cooling of the test specimen, optically observ-ing the first appearance of a cloud of wax crystals andrecording the temperature of the specimen described in detailin Annex A1.6.2 The apparatus shall be equipped with a specimen
31、 cup,optical detector array, light source, digital display, Peltierdevice, and a specimen temperature measuring device.6.3 The Peltier device shall be capable of heating or coolingthe test specimen at a constant rate of 1.5 6 0.1C/min.6.4 The temperature measuring device in the specimen cupshall be
32、capable of measuring the temperature of the testspecimen from 40 to +70C at a resolution of 0.1C.6.5 The apparatus shall be equipped with fittings to permitthe circulation of a liquid cooling medium, if required, to4The sole source of supply of the PhaseTechnology Cloud PointAnalyzer modelseries 10,
33、 30, 70, 70V, and 70X known to the committee at this time is PhaseTechnology, 11168 Hammersmith Gate, Richmond, B.C. Canada V7A 5H8. Thevarious model series mentioned above are differentiated by their cooling capacitiesand user interfaces; however, all of them are capable of covering the entiretempe
34、rature range specified in the scope. If you are aware of alternative suppliers,please provide this information to ASTM International Headquarters. Your com-ments will receive careful consideration at a meeting of the responsible technicalcommittee,1which you may attend.D5773 102remove heat generated
35、 by the Peltier device and other elec-tronic components of the apparatus.NOTE 4Some apparatus are designed to use ambient air as a coolingmedium. In such cases, a built-in fan is available to provide circulation ofair and there is no need for fittings as described for a liquid coolingmedium. The fun
36、ction of the cooling medium is to remove heat from theelectronic components. The choice of the cooling medium has no impactwhatsoever on the test results.6.6 The apparatus shall be equipped with fittings to permitthe circulation of purge gas to purge the test chamber contain-ing the specimen cup of
37、any atmospheric moisture.7. Reagents and Materials7.1 Cooling MediumAir, tap water, or other liquid heatexchange medium sufficient to remove heat generated by thePeltier device and other electronic components from theapparatus. To achieve specimen cooling to 40C, supplycirculation of liquid cooling
38、medium at +25C or lower to theapparatus. For an apparatus which relies on air as coolingmedium, the ambient air temperature has to be below +30C toachieve specimen cooling to 40C.7.2 Purge GasA gas such as air, nitrogen, helium, orargon with a dew point below the lowest operating temperatureof the a
39、nalyzer. (WarningCompressed gas under high pres-sure.) (WarningInert gas can be an asphyxiant when in-haled.)7.3 Precision VolumeDispensing Device, capable of dis-pensing 0.15 6 0.01 mL of sample.7.4 Cotton SwabsPlastic or paper shaft cotton swabs usedto clean the sample cup. (WarningThe use of swab
40、s withwooden shafts may damage the mirrored surface of thespecimen cup.)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 before they are tested. However, nosample should be heated more than ab
41、solutely necessary.8.3 The sample shall not be heated above 70C. When thesample is heated above 70C, allow the sample to cool below70C before filtering or inserting into the apparatus.8.4 When moisture is present in the sample, remove themoisture by a method, such as filtration through dry lint-free
42、filter paper, until the oil is perfectly clear, but make suchfiltration at a temperature at least 14C above the expectedcloud point.NOTE 5Moisture will be noticed in the sample as a separate phase oras a haze throughout the entire sample. Generally, a slight haze will notinterfere with the detection
43、 of the wax cloud.9. Preparation of Apparatus9.1 Prepare the instrument for operation in accordance withthe manufacturers instructions.9.2 Make liquid cooling medium connections if required(see Note 4) and ensure that they do not leak.9.3 Make purge gas connections and ensure that they do notleak.9.
44、4 Turn on the liquid cooling medium if required (see Note4).9.5 Turn on the purge gas.9.6 Turn on the main power switch of the analyzer.After theautomatic self diagnostics startup sequence is completed, theinstrument will display a READY message.10. Calibration and Standardization10.1 Ensure that al
45、l 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 Inspect the specimen cup to ensure it is clean and dry.If not, clean the c
46、up (see 11.3).11.2 Deliver 0.15 6 0.01 mLof specimen into the specimencup. Pipette, syringe, or precision positive-displacement de-vices are suitable for use in delivering the specimen.11.3 Clean the specimen out of the cup. The cup must becleaned to the point where no visible droplets of specimenre
47、main in the cup. Non-abrasive absorbent materials such ascotton swabs are suitable for use in cleaning the specimen cup.Cleaning solvents able to clean the specimen and compatiblewith the components of the apparatus can also be used.Naphtha, hexane, heptane, and toluene are suitable as cleaningsolve
48、nts.11.4 Repeat steps 11.2 and 11.3.11.5 Carefully measure 0.15 6 0.01 mL of specimen intothe specimen cup.11.6 Close and lock the test chamber lid.11.7 Select the PRE-HEAT menu on the apparatus if theexpected cloud point is less than 14C below the specimenambient temperature. The specimen ambient t
49、emperature isdisplayed on the front panel of the apparatus. With thisselection, the apparatus will automatically heat the specimen toa starting temperature of 50C prior to cooling. If the PRE-HEAT menu is not selected, the apparatus will cool thespecimen from ambient temperature without any initial heat-ing. When the cloud point is expected to be higher than 35C,select a higher starting temperature according to manufactur-ers instructions. The highest starting temperature that can beprogrammed is 70C.11.8 Start the operation o
