1、Designation: D7346 14D7346 15Standard Test Method forNo Flow Point and Pour Point of Petroleum Products andLiquid Fuels1This 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
2、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.1. Scope*1.1 This test method covers the determination of the no flow point temperature and pour point of petroleum produc
3、ts products,liquid fuels, biodiesel, and biodiesel blends using an automatic instrument.1.2 The measuring range of the apparatus is from 95 C to 45 C, however the precision statements were derived only fromsamples with no flow point temperatures from 77 C to +2 C and samples with pour point in the t
4、emperature range of 58 Cto +12 C.1.3 Pour point results from this test method can be reported at 1 C or 3 C intervals.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 This standard does not purport to address all of the
5、 safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D97 Test Method for Pour Point
6、 of Petroleum ProductsD4057 Practice for Manual Sampling of Petroleum and Petroleum ProductsD4177 Practice for Automatic Sampling of Petroleum and Petroleum ProductsD6300 Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products and LubricantsD6708 Practice
7、 for Statistical Assessment and Improvement of Expected Agreement Between Two Test Methods that Purportto Measure the Same Property of a Material3. Terminology3.1 Definitions:3.1.1 pour point, nin petroleum products, the lowest temperature at which movement of the test specimen is observed underthe
8、prescribed conditions of the test.3.2 Definitions of Terms Specific to This Standard:3.2.1 no-flow point, nin petroleum products, the temperature of the test specimen at which a wax crystal structure formationor viscosity increase, or both, is sufficient to impede movement of the surface of the test
9、 specimen under the conditions of the test.3.2.1.1 DiscussionThe no-flow point occurs when, upon cooling, the formation of wax crystal structures or viscosity increase, or both, haveprogressed to the point where the applied observation device no longer detects movement under the conditions of the te
10、st.1 This test method is under the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.07 on Flow Properties.Current edition approved May 1, 2014July 1, 2015. Published June 2014July 2015. Originally approved in 20
11、07. Last previous edition approved in 20122014 asD7346 12. 14. DOI: 10.1520/D7346-14.10.1520/D7346-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards D
12、ocument Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, AST
13、M recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO
14、Box C700, West Conshohocken, PA 19428-2959. United States14. Summary of Test Method4.1 After inserting the test specimen into the automatic no flow point apparatus and initiating the program, the test specimenis heated, if necessary, to a starting temperature and then cooled by prescribed rates. The
15、 test specimen is continuously tested forflow characteristics by continuously monitoring the air pressure variation inside the test specimen vial. When the specimen is stillfluid, its movement will partially compensate for the reduction in air pressure in the test chamber above the test specimen sur
16、face.At some temperature the pressure measuring system detects a pressure decrease due to incapability of the test specimen to flowcaused by a crystal structure formation in the specimen or its viscosity increase, or both. This temperature is recorded as no flowpoint with a resolution of 0.1 C. The
17、pour point is recorded by rounding the no flow point temperature to either the next warmer1 C interval or 3 C interval. The test specimen is then reheated to allow for removal from the test chamber.5. Significance and Use5.1 The no flow point of a petroleum product is an index of the lowest temperat
18、ure of its utility for some applications. Flowcharacteristics, such as no flow point, can be critical for the proper operation of lubricating systems, fuel systems, and pipelineoperations.5.2 Petroleum blending operations require precise measurement of the no flow point.5.3 This test method can dete
19、rmine the temperature of the test specimen with a resolution of 0.1 C at which either crystals haveformed or viscosity has increased sufficiently, or both, to impede flow of the petroleum product.5.4 The pour point of a petroleum product is an index of the lowest temperature of its utility for certa
20、in applications. Flowcharacteristics, like pour point, can be critical for the correct operation of lubricating oil systems, fuel systems, and pipelineoperations.5.5 Petroleum blending operations require precise measurement of the pour point.5.6 Pour point results from this test method can be report
21、ed at either 1 C or 3 C intervals.5.7 This test method yields a pour point in a format similar to Test Method D97/IP15 when the 3 C interval results are reported.5.8 This test method has better repeatability and reproducibility relative to Test Method D97/IP15 as measured in the 2011interlaboratory
22、test program (see 13.1.2).6. Apparatus (see Annex A1)6.1 Automatic No Flow Point Apparatus3The apparatus consists of a microprocessorcontrolled test specimen chamber thatis capable of heating and cooling the test specimen at required rate, measuring the pressure inside the test specimen vial, andrec
23、ording the temperature of the test specimen chamber. A detailed description of the apparatus is provided in Annex A1.6.2 The apparatus shall be equipped with a thermostatically controlled specimen chamber, digital display, cooling and heatingsystems, pressure measuring system, and a specimen chamber
24、 temperature measuring device.6.3 The temperature measuring device in the specimen chamber shall be capable of measuring the temperature from 105 Cto 60 C at a resolution of 0.1 C.6.4 Ultrasonic Bath, Unheated(optional), with an operating frequency between 25 kHz to 60 kHz and a typical power output
25、of 100 W, of suitable dimensions to hold container(s) placed inside of bath, for use in effectively dissipating and removing airor gas bubbles that can be entrained in viscous sample types prior to analysis. It is permissible to use ultrasonic baths with operatingfrequencies and power outputs outsid
26、e this range, however it is the responsibility of the laboratory to conduct a data comparisonstudy to confirm that results determined with and without the use of such ultrasonic baths does not materially impact results.7. Reagents and Materials7.1 Specimen VialDisposable, clear glass cylinder with c
27、losed 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 application.7.2 Specimen Vial StopperDisposable, proprietary designed for use in this apparatus.7.3
28、MicropipetteCapable of delivering 0.5 mL 6 0.1 mL of sample. Positive displacement type micropipette with capillarypiston is preferred for use. Air-displacement type micropipettes are not recommended for viscous samples.3 The sole source of supply of the apparatus known to the committee at this time
29、 is 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 consideration at a meetingof the responsible technical committee,1 whic
30、h you may attend.D7346 1528. Sampling8.1 Obtain a sample in accordance with Practice D4057 or D4177.8.2 At least 1 mL of sample is required for each test.8.3 Samples of very viscous materials can be warmed until they are reasonably fluid before they are transferred; however, nosample shall be heated
31、 more than is absolutely necessary. The sample shall not be heated and transferred into the test specimencup unless its temperature is 70 C or lower.NOTE 2In the event the sample has been heated above this temperature, allow the sample to cool until its temperature is below 70 C beforetransferring i
32、t.8.4 For some sample types, such as viscous lube oils that are prone to having entrained air or gas bubbles present in the sample,the use of an ultrasonic bath (see 6.4) without the heater turned on (if so equipped), has been found effective in dissipating bubblestypically within 1 min.9. Preparati
33、on of Apparatus9.1 Prepare the apparatus for operation in accordance with the manufacturers instructions.10. Calibration and Standardization10.1 Ensure that all of the manufacturers instructions for calibration of the mechanical and electronic systems and operationof the apparatus are followed.10.2
34、To verify the performance of the apparatus, a sample for which extensive data has been obtained by no flow point testmethod may be used. Such verification materials can also be prepared from intra-company cross checks.11. Procedure11.1 Draw 0.5 mL6 0.1 mLof sample into a micropipette and transfer th
35、e specimen into a new clean, dry specimen vial. Whennecessary, heat the sample in a water bath or oven until it is just sufficiently fluid to transfer. Samples with an expected no flowpoint above 25 C or which appear solid at room temperature can be heated above 45 C but shall not be heated above 70
36、 C (seeNote 2).NOTE 3Some samples like residual fuels, black oils, and cylinder stock have been known to be sensitive to thermal history. In the case where suchsample is tested, refer to Test Method D97 for sample treatment prior testing.11.2 Place a new clean, dry specimen vial stopper on the speci
37、men vial and insert the assembly into the apparatus. Start theoperation of the apparatus according to the manufacturers instructions.When the expected no flow point of the specimen is known,program it in the apparatus as EP (expected point) and start test sequence. From this point up to and includin
38、g the termination ofthe test, recording and reporting of the result, the apparatus automatically controls the procedure.11.3 The apparatus adjusts the specimen chamber to a preselected starting temperature. By default, the preselected startingtemperature is 25 C. Alternatively, the operator can prep
39、rogram a defined starting temperature between 25 C and 60 C, ifdesired. When the expected no flow point is known and programmed in the apparatus, the starting temperature shall be at least30 C warmer. In the event that the preselected starting temperature is programmed lower than 30 C above the expe
40、cted no flowpoint, the apparatus shall heat the specimen chamber to a starting temperature at least 30 C above the expected no flow point, butnot more than 60 C.11.4 When the expected no flow point of the specimen is not known, once the starting temperature is reached (see 11.3) thespecimen chamber
41、is cooled at a rate of 1.5 Cmin 6 0.15 Cmin.11.5 At the same time the cooling begins, the pressure measurement system is engaged to continuously monitor specimenbehavior. When a decrease in pressure, as determined by the apparatus, is measured in the specimen vial, which signifies that thetest speci
42、men has ceased to flow due to a crystal structure formation in the specimen or its viscosity increase, or both, thetemperature of the specimen chamber is recorded as the no flow point and held on a digital display. The test chamber is thanreheated and the test sequence is terminated.11.6 When a no f
43、low point is detected prematurely, as determined by the apparatus, the specimen is automatically reheated toa higher starting temperature, at least 30 C warmer than the temperature of premature detection, and then cooled as described in11.4 until the no flow point is detected as described in 11.5.NO
44、TE 4Some typical examples of premature no flow point are: when the NFP is detected during the fast cooling phase or when the NFP is detectedless than 30 C from the starting temperature.11.7 When the expected no flow point of the specimen is known, and programmed into the apparatus, once the starting
45、temperature (see 11.3) is reached, the specimen chamber is cooled at a rate of 10 Cmin 6 1 Cmin until 30 C warmer thanthe programmed expected no flow point, then the cooling rate is adjusted to 1.5 Cmin 6 0.15 Cmin and the no flow pointtemperature is detected as described in 11.5.D7346 15311.8 When
46、reporting of the pour point is desired, round the no flow point temperature in 11.5 to the next warmer 1 C intervalor 3 C interval, as specified, and record. Some apparatus are capable of performing this automatically.12. Report12.1 Report the temperature recorded in 11.5 with resolution of 0.1 C, a
47、s the no-flow point in accordance with Test MethodD7346.12.2 Report the temperature recorded in 11.8 as the pour point 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 determined by th
48、e statistical examination of the interlaboratory test resultsis as follows:13.1.1 No Flow Point:413.1.1.1 RepeatabilityThe difference between two results obtained by the same operator with the same apparatus underconstant operating conditions on identical test material would, in the long run, in the
49、 normal and correct operation of this 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 two single and independent results obtained by different operators workingin different laboratories on identical test material would, in the long run, in the normal and correct operation of this test method,exceed the following only in one case in twenty.2.62 C Range: 77 C to +2 C13.1.2 Pour Point at 3 C Intervals:513.1.2.1 Repea
