1、Designation: D5773 15Designation: IP 446/09Standard 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 rev
2、ision, 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 ofpetroleu
3、m 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 obtaining co
4、mparative 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
5、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 asstandard. No other un
6、its 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 applica-bility of reg
7、ulatory 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 Energy Institute Standar
8、d:3IP 219 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 veget
9、able oil 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
10、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 occurs uponcooling und
11、er 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 under the jurisdict
12、ion 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 as D5773 10. DOI:10.
13、1520/D5773-15.2For 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 Institute, 61 New Cavend
14、ish 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 cloud point is thetemp
15、erature 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 called “wax crystals.
16、”3.1.3.2 DiscussionThe purpose 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 f
17、rom a single liquid phase 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 aspecimen, when
18、 the appearance of the cloud is determinedunder the conditions 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 est
19、ablished for Test MethodD2500, although according to interlaboratory examination, theresults have been determined to be equivalent to Test MethodD2500.3.2.2 constant cooling rate method, n in cloud point testmethods, test procedure using prescribed cooling rate, speci-men receptacle, and optical sys
20、tem for detection of crystalformation.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 devicec
21、onstructed with dissimilar 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, calc
22、ulated by rounding theresults of this test method to the next lower integer.3.2.4.1 DiscussionThis test method produces results with0.1 C resolution. Should the user wish to provide results witha similar format to Test Method D2500, then this calculationcan be performed. Some apparatus can perform t
23、his calculationautomatically.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 Cmin 6 0.1 Cminwhile continuously being illuminated by a light source(A1.1.4). The specimen is continuously monitored by an arrayof optical detectors (
24、A1.1.5, Fig. A1.1) for the first appearanceof a cloud of wax crystals. The detectors are sufficient innumber to ensure that any solid phase hydrocarbon crystals thatmay form are detected. The temperature at which the appear-ance of a cloud of wax crystals is first detected in the specimenis recorded
25、 to 0.1 C resolution. When the recorded tempera-ture is rounded to the next lower integer temperature, it isdesignated as the D2500/IP 219 equivalent cloud point per TestMethod D5773.5. Significance and Use5.1 The cloud point of petroleum products and biodieselfuels is an index of the lowest tempera
26、ture of their utility forcertain applications. 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 crystal
27、s have formed sufficiently tobe observed as a cloud with a resolution of 0.1 C.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 0.1 C result is rounded to the next lower integer.5.5 This test
28、 method determines the cloud point in a shorterperiod of time than Test Method D2500.NOTE 2In cases of samples with cloud points near ambienttemperatures, 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
29、 not require the use of a mechani-cal 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
30、method consists of a test chambercontrolled 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 apparat
31、us shall be equipped with a specimen 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 Cmin 60.1 Cmin.4The sole source of suppl
32、y of the Phase Technology Cloud PointAnalyzer modelseries 10, 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;
33、 however, all of them are capable of covering the entiretemperature 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 technicalc
34、ommittee,1which you may attend.D5773 1526.4 The temperature measuring device in the specimen cupshall be capable of measuring the temperature of the testspecimen from 40 C to +70 C at a resolution of 0.1 C.6.5 The apparatus shall be equipped with fittings to permitthe circulation of a liquid cooling
35、 medium, if required, toremove heat generated 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
36、described for a liquid coolingmedium. The function 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
37、test chamber contain-ing the specimen cup of 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
38、 to 40 C, supplycirculation of liquid cooling medium at +25 C or lower to theapparatus. For an apparatus which relies on air as coolingmedium, the ambient air temperature has to be below +30 C toachieve specimen cooling to 40 C.7.2 Purge GasA gas such as air, nitrogen, helium, orargon with a dew poi
39、nt below the lowest operating temperatureof the analyzer. (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 mL 6 0.01 mL of sample.7.4 Cotton SwabsPlastic or paper shaft cotton swabs
40、usedto clean the sample cup. (WarningThe use of swabs 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 tes
41、ted. 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, remove themoistur
42、e 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 5Moisture will be noticed in the sample as a separate phase oras a haze throughout the entire sample. Gener
43、ally, 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 Make liquid cooling medium connections if required(see Note 4) and ensure that they do not leak.9.3 Make
44、purge gas connections and ensure that they do notleak.9.4 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 messag
45、e.10. Calibration and Standardization10.1 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 Inspect the specim
46、en cup to ensure it is clean and dry.If not, clean the cup (see 11.3).11.2 Deliver 0.15 mL 6 0.01 mL of specimen into thespecimen cup. Pipette, syringe, or precision positive-displacement devices are suitable for use in delivering thespecimen.11.3 Clean the specimen out of the cup. The cup must becl
47、eaned to the point where no visible droplets of specimenremain 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,
48、hexane, heptane, and toluene are suitable as cleaningsolvents.11.4 Repeat steps 11.2 and 11.3.11.5 Carefully measure 0.15 mL6 0.01 mL of specimeninto the 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 14 C
49、below the specimenambient temperature. The specimen ambient temperature isdisplayed on the front panel of the apparatus. With thisselection, the apparatus will automatically heat the specimen toa starting temperature of 50 C prior to cooling. If thePRE-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 35 C,select a higher starting temperature according to manufactur-ers instructions. The highest start
