1、Designation: D7346 14Standard Test Method forNo Flow Point and Pour Point of Petroleum Products1This standard is issued under the fixed designation D7346; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、 number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the determination of the no flowpoint temperature and pour point of petroleum products usingan automatic inst
3、rument.1.2 The measuring range of the apparatus is from 95 C to45 C, however the precision statements were derived onlyfrom samples with no flow point temperatures from 77 C to+2 C and samples with pour point in the temperature range of58 C to +12 C.1.3 Pour point results from this test method can b
4、e reportedat 1 C or 3 C intervals.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user
5、of this standard to establish appro-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 ProductsD4057 Practice for Manual Sampling of Petroleum andPetroleum P
6、roductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD6300 Practice for Determination of Precision and BiasData for Use in Test Methods for Petroleum Products andLubricantsD6708 Practice for Statistical Assessment and Improvementof Expected Agreement Between Two Test Method
7、s thatPurport to Measure the Same Property of a Material3. Terminology3.1 Definitions:3.1.1 pour point, nin petroleum products, the lowesttemperature at which movement of the test specimen isobserved under the prescribed conditions of the test.3.2 Definitions of Terms Specific to This Standard:3.2.1
8、 no-flow point, nin petroleum products, the tempera-ture of the test specimen at which a wax crystal structureformation or viscosity increase, or both, is sufficient to impedemovement of the surface of the test specimen under theconditions of the test.3.2.1.1 DiscussionThe no-flow point occurs when,
9、 uponcooling, the formation of wax crystal structures or viscosityincrease, or both, have progressed to the point where theapplied observation device no longer detects movement underthe conditions of the test.4. Summary of Test Method4.1 After inserting the test specimen into the automatic noflow po
10、int apparatus and initiating the program, the testspecimen is heated, if necessary, to a starting temperature andthen cooled by prescribed rates. The test specimen is continu-ously tested for flow characteristics by continuously monitor-ing the air pressure variation inside the test specimen vial.Wh
11、en the specimen is still fluid, its movement will partiallycompensate for the reduction in air pressure in the test chamberabove the test specimen surface. At some temperature thepressure measuring system detects a pressure decrease due toincapability of the test specimen to flow caused by a crystal
12、structure formation in the specimen or its viscosity increase, orboth. This temperature is recorded as no flow point with aresolution of 0.1 C. The pour point is recorded by roundingthe no flow point temperature to either the next warmer 1 Cinterval or 3 C interval. The test specimen is then reheate
13、d toallow for removal from the test chamber.5. Significance and Use5.1 The no flow point of a petroleum product is an index ofthe lowest temperature of its utility for some applications. Flowcharacteristics, such as no flow point, can be critical for theproper operation of lubricating systems, fuel
14、systems, andpipeline operations.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 May 1, 2014. Published June 2014. Originallyapproved
15、 in 2007. Last previous edition approved in 2012 as D7346 12. DOI:10.1520/D7346-14.2For 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 pa
16、ge onthe ASTM website.*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 States15.2 Petroleum blending operations require precise measure-ment of the no flow point.5.3 This test m
17、ethod can determine the temperature of thetest specimen with a resolution of 0.1 C at which eithercrystals have formed or viscosity has increased sufficiently, orboth, to impede flow of the petroleum product.5.4 The pour point of a petroleum product is an index of thelowest temperature of its utilit
18、y for certain applications. Flowcharacteristics, like pour point, can be critical for the correctoperation of lubricating oil systems, fuel systems, and pipelineoperations.5.5 Petroleum blending operations require precise measure-ment of the pour point.5.6 Pour point results from this test method ca
19、n be reportedat either 1 C or 3 C intervals.5.7 This test method yields a pour point in a format similarto Test Method D97/IP15 when the 3 C interval results arereported.5.8 This test method has better repeatability and reproduc-ibility relative to Test Method D97/IP15 as measured in the2011 interla
20、boratory test program (see 13.1.2).6. Apparatus (see Annex A1)6.1 Automatic No Flow Point Apparatus3The apparatusconsists of a microprocessorcontrolled test specimen chamberthat is capable of heating and cooling the test specimen atrequired rate, measuring the pressure inside the test specimenvial,
21、and recording the temperature of the test specimenchamber. A detailed description of the apparatus is provided inAnnex A1.6.2 The apparatus shall be equipped with a thermostaticallycontrolled specimen chamber, digital display, cooling andheating systems, pressure measuring system, and a specimencham
22、ber temperature measuring device.6.3 The temperature measuring device in the specimenchamber shall be capable of measuring the temperature from105 C to 60 C at a resolution of 0.1 C.6.4 Ultrasonic Bath, Unheated(optional), with an operat-ing frequency between 25 kHz to 60 kHz and a typical poweroutp
23、ut of 100 W, of suitable dimensions to hold container(s)placed inside of bath, for use in effectively dissipating andremoving air or gas bubbles that can be entrained in viscoussample types prior to analysis. It is permissible to use ultra-sonic baths with operating frequencies and power outputsouts
24、ide this range, however it is the responsibility of thelaboratory to conduct a data comparison study to confirm thatresults determined with and without the use of such ultrasonicbaths does not materially impact results.7. Reagents and Materials7.1 Specimen VialDisposable, clear glass cylinder withcl
25、osed flat bottom, 1 mL capacity.Dimensions:Outer diameter: 8.0 mm to 8.3 mmWall thickness: 0.75 mm to 0.85 mmOuter length: 39.25 mm to 40.25 mmNOTE 1Standard NWV type vial was found suitable for the applica-tion.7.2 Specimen Vial StopperDisposable, proprietary de-signed for use in this apparatus.7.3
26、 MicropipetteCapable of delivering 0.5 mL 6 0.1 mLof sample. Positive displacement type micropipette with cap-illary piston is preferred for use. Air-displacement type mi-cropipettes are not recommended for viscous samples.8. Sampling8.1 Obtain a sample in accordance with Practice D4057 orD4177.8.2
27、At least 1 mL of sample is required for each test.8.3 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 c
28、up unless its temperature is 70 C or lower.NOTE 2In the event the sample has been heated above thistemperature, allow the sample to cool until its temperature is below 70 Cbefore transferring it.8.4 For some sample types, such as viscous lube oils that areprone to having entrained air or gas bubbles
29、 present in thesample, the use of an ultrasonic bath (see 6.4) without theheater turned on (if so equipped), has been found effective indissipating bubbles typically within 1 min.9. Preparation of Apparatus9.1 Prepare the apparatus for operation in accordance withthe manufacturers instructions.10. C
30、alibration and Standardization10.1 Ensure that all of the manufacturers instructions forcalibration of the mechanical and electronic systems andoperation of the apparatus are followed.10.2 To verify the performance of the apparatus, a samplefor which extensive data has been obtained by no flow point
31、test method may be used. Such verification materials can alsobe prepared from intra-company cross checks.11. Procedure11.1 Draw 0.5 mL 6 0.1 mL of sample into a micropipetteand transfer the specimen into a new clean, dry specimen vial.When necessary, heat the sample in a water bath or oven untilit i
32、s just sufficiently fluid to transfer. Samples with an expectedno flow point above 25 C or which appear solid at roomtemperature can be heated above 45 C but shall not be heatedabove 70 C (see Note 2).NOTE 3Some samples like residual fuels, black oils, and cylinder3The sole source of supply of the a
33、pparatus known to the committee at this timeis ISL model MPP 5Gs Analyzer, available from ISL, B.P. 70285 14653 Verson,France. If you are aware of alternative suppliers, please provide this information toASTM International Headquarters. Your comments will receive careful consider-ation at a meeting
34、of the responsible technical committee,1which you may attend.D7346 142stock have been known to be sensitive to thermal history. In the casewhere such sample is tested, refer to Test Method D97 for sampletreatment prior testing.11.2 Place a new clean, dry specimen vial stopper on thespecimen vial and
35、 insert the assembly into the apparatus. Startthe operation of the apparatus according to the manufacturersinstructions. When the expected no flow point of the specimenis known, program it in the apparatus as EP (expected point)and start test sequence. From this point up to and including theterminat
36、ion of the test, recording and reporting of the result, theapparatus automatically controls the procedure.11.3 The apparatus adjusts the specimen chamber to apreselected starting temperature. By default, the preselectedstarting temperature is 25 C. Alternatively, the operator canpreprogram a defined
37、 starting temperature between 25 C and60 C, if desired. When the expected no flow point is knownand programmed in the apparatus, the starting temperatureshall be at least 30 C warmer. In the event that the preselectedstarting temperature is programmed lower than 30 C abovethe expected no flow point,
38、 the apparatus shall heat thespecimen chamber to a starting temperature at least 30 Cabove the expected no flow point, but not more than 60 C.11.4 When the expected no flow point of the specimen is notknown, once the starting temperature is reached (see 11.3) thespecimen chamber is cooled at a rate
39、of 1.5 C/min 60.15 C/min.11.5 At the same time the cooling begins, the pressuremeasurement system is engaged to continuously monitorspecimen behavior. When a decrease in pressure, as determinedby the apparatus, is measured in the specimen vial, whichsignifies that the test specimen has ceased to flo
40、w due to acrystal structure formation in the specimen or its viscosityincrease, or both, the temperature of the specimen chamber isrecorded as the no flow point and held on a digital display. Thetest chamber is than reheated and the test sequence is termi-nated.11.6 When a no flow point is detected
41、prematurely, asdetermined by the apparatus, the specimen is automaticallyreheated to a higher starting temperature, at least 30 C warmerthan the temperature of premature detection, and then cooled asdescribed in 11.4 until the no flow point is detected asdescribed in 11.5.NOTE 4Some typical examples
42、 of premature no flow point are: whenthe NFP is detected during the fast cooling phase or when the NFP isdetected less than 30 C from the starting temperature.11.7 When the expected no flow point of the specimen isknown, and programmed into the apparatus, once the startingtemperature (see 11.3) is r
43、eached, the specimen chamber iscooled at a rate of 10 C/min 6 1 C/min until 30 C warmerthan the programmed expected no flow point, then the coolingrate is adjusted to 1.5 C/min 6 0.15 C/min and the no flowpoint temperature is detected as described in 11.5.11.8 When reporting of the pour point is des
44、ired, round theno flow point temperature in 11.5 to the next warmer 1 Cinterval or 3 C interval, as specified, and record. Someapparatus are capable of performing this automatically.12. Report12.1 Report the temperature recorded in 11.5 with resolu-tion of 0.1 C, as the no-flow point in accordance w
45、ith TestMethod D7346.12.2 Report the temperature recorded in 11.8 as the pourpoint at either the 1 C interval or 3 C interval as specified inaccordance with Test Method D7346.13. Precision and Bias13.1 PrecisionThe precision of this test method as deter-mined by the statistical examination of the in
46、terlaboratory testresults is as follows:13.1.1 No Flow Point:413.1.1.1 RepeatabilityThe difference between two resultsobtained by the same operator with the same apparatus underconstant operating conditions on identical test material would,in the long run, in the normal and correct operation of this
47、 testmethod, exceed the following only in one case in twenty.1.93 C Range: 77 C to +2 C13.1.1.2 ReproducibilityThe difference between twosingle and independent results obtained by different operatorsworking in different laboratories on identical test materialwould, in the long run, in the normal and
48、 correct operation ofthis test method, exceed the following only in one case intwenty.2.62 C Range: 77 C to +2 C13.1.2 Pour Point at 3 C Intervals:513.1.2.1 RepeatabilityThe difference between two resultsobtained by the same operator with the same apparatus underconstant operating conditions on iden
49、tical test material would,in the long run, in the normal and correct operation of this testmethod, exceed the following only in one case in twenty.0.0384 50 2 X! range:258 to112 (1)X = result in C.13.1.2.2 ReproducibilityThe difference between twosingle and independent 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 the following only in one case intwenty.0.0535 50 2
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