1、Designation: D5191 18D5191 18aStandard Test Method forVapor Pressure of Petroleum Products and Liquid Fuels(Mini Method)1This standard is issued under the fixed designation D5191; 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.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope*1.1 This test method cover
3、s the use of automated vapor pressure instruments to determine the total vapor pressure exerted invacuum by air-containing, volatile, liquid petroleum products, products and liquid fuels, including automotive spark-ignition fuelswith or without oxygenates and with ethanol blends up to 85 % (volume f
4、raction) (see Note 1). This test method is suitable fortesting samples with boiling points above 0 C (32 F) that exert a vapor pressure between 7 kPa and 130 kPa (1.0 psi and 18.6 psi)at 37.8 C (100 F) at a vapor-to-liquid ratio of 4:1. Measurements are made on liquid sample sizes in the range from
5、1 mL to10 mL. No account is made for dissolved water in the sample.NOTE 1The precision (see Section 16) using 1 L containers was determined in a 2003 interlaboratory study (ILS);2 the precision using 250 mLcontainers was determined in a 2016 ILS.3NOTE 2Samples can also be tested at other vapor-to-li
6、quid ratios, temperatures, and pressures, but the precision and bias statements need not apply.NOTE 3The ILS conducted in 1988, 1991, 2003, and 2016 to determine the precision statements in Test Method D5191 did not include any crudeoil in the sample sets. Test Method D6377, as well as IP 481, have
7、been shown to be suitable for vapor pressure measurements of crude oils.1.1.1 Some gasoline-oxygenate blends may show a haze when cooled to 0 C to 1 C. If a haze is observed in 8.5, it shall beindicated in the reporting of results. The precision and bias statements for hazy samples have not been det
8、ermined (see Note 15).1.2 This test method is suitable for calculation of the dry vapor pressure equivalent (DVPE) of gasoline and gasoline-oxygenateblends by means of a correlation equation (see Eq 1 in 14.2). The calculated DVPE very closely approximates the dry vaporpressure that would be obtaine
9、d on the same material when tested by Test Method D4953.1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided forinformation only and are not considered standard.1.4 WARNINGMercury has been designated by many regulatory agencies
10、 as a hazardous substance that can cause seriousmedical issues. Mercury, or its vapor, has been demonstrated to be hazardous to health and corrosive to materials. Use Cautionwhen handling mercury and mercury-containing products. See the applicable product Safety Data Sheet (SDS) for additionalinform
11、ation. The potential exists that selling mercury or mercury-containing products, or both, is prohibited by local or nationallaw. Users must determine legality of sales in their location.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is t
12、he responsibilityof the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability ofregulatory limitations prior to use. For specific safety warning statements, see 7.2 through 7.8.1.6 This international standard was developed in accor
13、dance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.1 This test method is under the ju
14、risdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.08 on Volatility.Current edition approved June 1, 2018Dec. 1, 2018. Published September 2018February 2019. Originally approved in 1991. Last previous edition approv
15、ed in 20152018as D5191 15. 18. DOI: 10.1520/D5191-18.10.1520/D5191-18A.2 Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:D02-1619. Contact ASTM CustomerService at serviceastm.org.3 Research Report IP 394 (EN 130161)13016-1) and
16、IP 619 (EN 130163)13016-3) 2016, available from the Energy Institute, 61 New Cavendish Street, London W1G7AR, UK , email: ILSenergyinst.org.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
17、version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM 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
18、section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12. Referenced Documents2.1 ASTM Standards:4D2892 Test Method for Distillation of Crude Petroleum (15-Theoretical Plate Column)D4057 Practice fo
19、r Manual Sampling of Petroleum and Petroleum ProductsD4953 Test Method for Vapor Pressure of Gasoline and Gasoline-Oxygenate Blends (Dry Method)D5798 Specification for Ethanol Fuel Blends for Flexible-Fuel Automotive Spark-Ignition EnginesD6299 Practice for Applying Statistical Quality Assurance and
20、 Control Charting Techniques to Evaluate Analytical Measure-ment System PerformanceD6377 Test Method for Determination of Vapor Pressure of Crude Oil: VPCRx (Expansion Method)D6378 Test Method for Determination of Vapor Pressure (VPX) of Petroleum Products, Hydrocarbons, and Hydrocarbon-Oxygenate Mi
21、xtures (Triple Expansion Method)D7717 Practice for Preparing Volumetric Blends of Denatured Fuel Ethanol and Gasoline Blendstocks for Laboratory Analysis2.2 IP Standard:IP 481 Test Method for Determination of the Air Saturated Vapour Pressure (ASVP) of Crude Oil53. Terminology3.1 Definitions:3.1.1 f
22、uel ethanol (Ed75Ed85), nblend of ethanol and hydrocarbon, of which the ethanol portion is nominally 75 to 85volume % denatured fuel ethanol.3.2 Definitions of Terms Specific to This Standard:3.2.1 absolute vapor pressure, nthe pressure of the air-free sample. It is calculated from the total vapor p
23、ressure of the sampleby subtracting out the partial pressure of the dissolved air.3.2.2 dry vapor pressure equivalent (DVPE), na value calculated by a correlation equation (see 14.2) from the total vaporpressure.3.2.2.1 DiscussionThe DVPE is expected to be equivalent to the value obtained on the sam
24、ple by Test Method D4953, Procedure A.3.2.3 total vapor pressure (Ptot),nthe observed pressure measured in the experiment that is the sum of the partial pressure ofthe sample and the partial pressure of the dissolved air.3.3 Abbreviations:3.3.1 DVPEdry vapor pressure equivalent3.3.2 Ptottotal vapor
25、pressure4. Summary of Test Method4.1 A known volume of chilled, air-saturated sample is introduced into a thermostatically controlled, evacuated test chamber,or a test chamber with a moveable piston that expands the volume after sample introduction, the internal volume of which is fivetimes that of
26、the total test specimen introduced into the chamber. After introduction into the test chamber, the test specimen isallowed to reach thermal equilibrium at the test temperature, 37.8 C (100 F). The resulting rise in pressure in the chamber ismeasured using a pressure transducer sensor and indicator.
27、Only total pressure measurements (sum of the partial pressure of thesample and the partial pressure of the dissolved air) are used in this test method, although some instruments can measure theabsolute pressure of the sample as well.4.2 The measured total vapor pressure is converted to a dry vapor p
28、ressure equivalent (DVPE) by use of a correlation equation(see Eq 1 in 14.2).5. Significance and Use5.1 Vapor pressure is a very important physical property of volatile liquids.5.2 The vapor pressure of gasoline and gasoline-oxygenate blends is regulated by various government agencies.5.3 Specificat
29、ions for volatile petroleum products generally include vapor pressure limits to ensure products of suitablevolatility performance.4 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume informati
30、on, refer to the standards Document Summary page on the ASTM website.5 Available from Energy Institute, 61 New Cavendish St., London, W1G 7AR, U.K., http:/www.energyinst.org.D5191 18a25.4 This test method is more precise than Test Method D4953, uses a small sample size (1 mL to 10 mL), and requires
31、about7 min to complete the test.6. Apparatus6.1 Vapor Pressure ApparatusThe type of apparatus suitable for use in this test method employs a small volume test chamberincorporating a transducer for pressure measurements and associated equipment for thermostatically controlling the chambertemperature
32、and for evacuating the test chamber prior to sample introduction or expanding the volume after sample introductionby a moveable piston.6.1.1 The test chamber shall be designed to contain between 5 mLand 50 mLof liquid and vapor and be capable of maintaininga vapor-to-liquid ratio between 3.95 to 1.0
33、0 and 4.05 to 1.00.NOTE 4The test chamber employed by the instruments used in generating the precision and bias statements were constructed of stainless steel,aluminum, or brass.NOTE 5Test chambers exceeding a 15 mL capacity can be used, but the precision and bias statements (see Section 16) are not
34、 known to apply.6.1.2 The pressure transducer shall have a minimum operational range from 0 kPa to 177 kPa (0 psi to 25.7 psi) with a minimumresolution of 0.1 kPa (0.01 psi) and a minimum accuracy of 60.8 kPa (60.12 psi). The pressure measurement system shall includeassociated electronics and readou
35、t devices to display the resulting pressure reading.6.1.3 A thermostatically controlled heater shall be used to maintain the test chamber at 37.8 C 6 0.1 C (100 F 6 0.2 F) forthe duration of the vapor pressure measurement.6.1.4 A platinum resistance thermometer shall be used for measuring the temper
36、ature of the test chamber with a resolution of0.1 C (0.2 F) and an accuracy of 0.1 C (0.2 F).6.1.5 The vapor pressure apparatus shall have provisions for introduction of the test specimen into an evacuated test chamber,or into a test chamber by a moveable piston, and for the cleaning or purging of t
37、he chamber following or preceding the test.6.2 Vacuum Pump, capable of reducing the pressure in the test chamber to less than 0.01 kPa (0.001 psi) absolute.6.3 Syringe, (optional, depending on sample introduction mechanism employed with each instrument) gas-tight, 1 mLto 20 mLcapacity with a 61 % or
38、 better accuracy and a 61 % or better precision. If a syringe is used to measure the sample volume, thecapacity of the syringe should not exceed two times the volume of the test specimen being dispensed.6.4 Iced Water Bath, Refrigerator, or Air Bath, for chilling the samples and syringe to temperatu
39、res between 0 C to 1 C (32 Fto 34 F).6.5 Pressure Measuring Device, capable of measuring local station pressure with an accuracy of 0.20 kPa (0.03 psi), or better,at the same elevation relative to sea level as the apparatus in the laboratory.6.5.1 When a mercury barometer is not used as the pressure
40、 measuring device, the calibration of the pressure measuring deviceemployed shall be periodically checked (with traceability to a nationally recognized standard) to ensure that the device remainswithin the required accuracy specified in 6.5.6.6 McLeod Vacuum Gage or Calibrated Electronic Vacuum Meas
41、uring Device for Calibration, to cover at least the range from0.01 kPa to 0.67 kPa (0.1 mm Hg to 5 mm Hg). The calibration of the electronic vacuum measuring device shall be regularlyverified in accordance with the annex section on Vacuum Sensors (A6.3) of Test Method D2892.7. Reagents and Materials
42、7.1 Purity of ReagentsUse chemicals of at least 99 % purity for verification of instrument performance (see Section 11).Unless otherwise indicated, it is intended that all reagents conform to the specifications of the Committee on Analytical Reagentsof the American Chemical Society where such specif
43、ications are available.6 Lower purities can be used, provided it is firstascertained that the reagent is of sufficient purity to permit its use without lessening the accuracy of the determination.7.1.1 The chemicals in sections 7.2, 7.3, 7.4, 7.7, and 7.8 (blended by mass with pentane) are suggested
44、 for verification ofinstrument performance (see Section 11), based on the reference fuels analyzed in the 2003 interlaboratory study (ILS)2 (see Table1) and 2014 interlaboratory study (ILS)7(see Table 2). Such reference fuels are not to be used for instrument calibration. Table 1and Table 2 identify
45、 the accepted reference value (ARV) and uncertainty limits, as well as the acceptable testing range for eachof the reference fuels listed.NOTE 6Verification fluids reported by 28 of the 29 D5191 data set participants in the 2003 ILS2 included the following (with number of data setsidentified in pare
46、nthesis): 2,2-dimethylbutane (18), cyclopentane (5), pentane (2), 2,3-dimethylbutane (1), 3-methylpentane (1), and methanol (1).7.2 Cyclopentane, (WarningCyclopentane is flammable and a health hazard).6 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washingto
47、n, DC. For Suggestions on the testing of reagents not listed bythe American Chemical Society, see Annual Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.7 Supporting
48、 data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:D02-1805. Contact ASTM CustomerService at serviceastm.org.D5191 18a37.3 2,2-Dimethylbutane, (Warning2,2-dimethylbutane is flammable and a health hazard).7.4 2,3-Dimethylbutane, (Warning2,3-d
49、imethylbutane is flammable and a health hazard).7.5 Methanol, (WarningMethanol is flammable and a health hazard).7.6 2-Methylpentane, (Warning2-methylpentane is flammable and a health hazard).7.7 Pentane, (WarningPentane is flammable and a health hazard).7.8 Toluene, (WarningToluene is flammable and a health hazard).8. Sampling8.1 General Requirements:8.1.1 The extreme sensitivity of vapor pressure measurements to losses through evaporation and the resulting changes incomposition is such as to require the utmost precaution and the
