1、Designation: D5191 18Standard Test Method forVapor Pressure of Petroleum Products (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 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.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope*1.1 This test method covers the use of automated va
3、porpressure instruments to determine the total vapor pressureexerted in vacuum by air-containing, volatile, liquid petroleumproducts, including automotive spark-ignition fuels with orwithout oxygenates and with ethanol blends up to 85 %(volume fraction) (see Note 1). This test method is suitable for
4、testing samples with boiling points above 0 C (32 F) thatexert a vapor pressure between 7 kPa and 130 kPa (1.0 psi and18.6 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 rangefrom 1 mL to 10 mL. No account is made for dissolved waterin th
5、e sample.NOTE 1The precision (see Section 16) using 1 L containers wasdetermined in a 2003 interlaboratory study (ILS);2the precision using250 mL containers was determined in a 2016 ILS.3NOTE 2Samples can also be tested at other vapor-to-liquid ratios,temperatures, and pressures, but the precision a
6、nd bias statements need notapply.NOTE 3The ILS conducted in 1988, 1991, 2003, and 2016 todetermine the precision statements in Test Method D5191 did not includeany crude oil in the sample sets. Test Method D6377, as well as IP 481,have been shown to be suitable for vapor pressure measurements of cru
7、deoils.1.1.1 Some gasoline-oxygenate blends may show a hazewhen cooled to 0 C to 1 C. If a haze is observed in 8.5,itshall be indicated in the reporting of results. The precision andbias statements for hazy samples have not been determined(see Note 15).1.2 This test method is suitable for calculatio
8、n of the dryvapor pressure equivalent (DVPE) of gasoline and gasoline-oxygenate blends by means of a correlation equation (see Eq 1in 14.2). The calculated DVPE very closely approximates thedry vapor pressure that would be obtained on the same materialwhen tested by Test Method D4953.1.3 The values
9、stated in SI units are to be regarded asstandard. The values given in parentheses after SI units areprovided for information only and are not considered standard.1.4 WARNINGMercury has been designated by manyregulatory agencies as a hazardous substance that can causeserious medical issues. Mercury,
10、or its vapor, has been dem-onstrated to be hazardous to health and corrosive to materials.Use Caution when handling mercury and mercury-containingproducts. See the applicable product Safety Data Sheet (SDS)for additional information. The potential exists that sellingmercury or mercury-containing pro
11、ducts, or both, is prohibitedby local or national law. Users must determine legality of salesin their location.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 of this standard to establish appro-priate safe
12、ty, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.For specific safety warning statements, see 7.2 through 7.8.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization esta
13、blished in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:4D2892 Test Method for Distillation of Crude Petroleum(15-Theor
14、etical Plate Column)D4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4953 Test Method for Vapor Pressure of Gasoline andGasoline-Oxygenate Blends (Dry Method)1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and
15、is the direct responsibility ofSubcommittee D02.08 on Volatility.Current edition approved June 1, 2018. Published September 2018. Originallyapproved in 1991. Last previous edition approved in 2015 as D5191 15. DOI:10.1520/D5191-18.2Supporting data have been filed at ASTM International Headquarters a
16、nd maybe obtained by requesting Research Report RR:D02-1619. ContactASTM CustomerService at serviceastm.org.3Research Report IP 394 (EN 130161) and IP 619 (EN 130163) 2016,available from the Energy Institute, 61 New Cavendish Street, London W1G 7AR,UK , email: ILSenergyinst.org.4For referenced ASTM
17、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.*A Summary of Changes section appears at the end of this standardCopyright ASTM In
18、ternational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standard
19、s, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1D5798 Specification for Ethanol Fuel Blends for Flexible-Fuel Automotive Spark-Ignition EnginesD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to
20、 Evaluate AnalyticalMeasurement System PerformanceD6377 Test Method for Determination of Vapor Pressure ofCrude Oil: VPCRx(Expansion Method)D6378 Test Method for Determination of Vapor Pressure(VPX) of Petroleum Products, Hydrocarbons, andHydrocarbon-Oxygenate Mixtures (Triple ExpansionMethod)D7717
21、Practice for Preparing Volumetric Blends of Dena-tured Fuel Ethanol and Gasoline Blendstocks for Labora-tory Analysis2.2 IP Standard:IP 481 Test Method for Determination of the Air SaturatedVapour Pressure (ASVP) of Crude Oil53. Terminology3.1 Definitions:3.1.1 fuel ethanol (Ed75Ed85), nblend of eth
22、anol andhydrocarbon, of which the ethanol portion is nominally 75 to85 volume % 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 pressure of thesample by subtracting ou
23、t the partial pressure of the dissolvedair.3.2.2 dry vapor pressure equivalent (DVPE), na valuecalculated by a correlation equation (see 14.2) from the totalvapor pressure.3.2.2.1 DiscussionThe DVPE is expected to be equivalentto the value obtained on the sample by Test Method D4953,Procedure A.3.2.
24、3 total vapor pressure (Ptot), nthe observed pressuremeasured in the experiment that is the sum of the partialpressure of the sample and the partial pressure of the dissolvedair.3.3 Abbreviations:3.3.1 DVPEdry vapor pressure equivalent3.3.2 Ptottotal vapor pressure4. Summary of Test Method4.1 A know
25、n volume of chilled, air-saturated sample isintroduced into a thermostatically controlled, evacuated testchamber, or a test chamber with a moveable piston thatexpands the volume after sample introduction, the internalvolume of which is five times that of the total test specimenintroduced into the ch
26、amber. After introduction into the testchamber, the test specimen is allowed to reach thermal equi-librium at the test temperature, 37.8 C (100 F). The resultingrise in pressure in the chamber is measured using a pressuretransducer sensor and indicator. Only total pressure measure-ments (sum of the
27、partial pressure of the sample and the partialpressure of the dissolved air) are used in this test method,although some instruments can measure the absolute pressureof the sample as well.4.2 The measured total vapor pressure is converted to a dryvapor pressure equivalent (DVPE) by use of a correlati
28、onequation (see Eq 1 in 14.2).5. Significance and Use5.1 Vapor pressure is a very important physical property ofvolatile liquids.5.2 The vapor pressure of gasoline and gasoline-oxygenateblends is regulated by various government agencies.5.3 Specifications for volatile petroleum products generallyinc
29、lude vapor pressure limits to ensure products of suitablevolatility performance.5.4 This test method is more precise than Test MethodD4953, uses a small sample size (1 mL to 10 mL), and requiresabout 7 min to complete the test.6. Apparatus6.1 Vapor Pressure ApparatusThe type of apparatus suit-able f
30、or use in this test method employs a small volume testchamber incorporating a transducer for pressure measurementsand associated equipment for thermostatically controlling thechamber temperature and for evacuating the test chamber priorto sample introduction or expanding the volume after sampleintro
31、duction by a moveable piston.6.1.1 The test chamber shall be designed to contain between5 mL and 50 mL of liquid and vapor and be capable ofmaintaining a vapor-to-liquid ratio between 3.95 to 1.00 and4.05 to 1.00.NOTE 4The test chamber employed by the instruments used ingenerating the precision and
32、bias statements were constructed of stainlesssteel, aluminum, or brass.NOTE 5Test chambers exceeding a 15 mL capacity can be used, butthe precision and bias statements (see Section 16) are not known to apply.6.1.2 The pressure transducer shall have a minimum opera-tional range from 0 kPa to 177 kPa
33、(0 psi to 25.7 psi) with aminimum resolution of 0.1 kPa (0.01 psi) and a minimumaccuracy of 60.8 kPa (60.12 psi). The pressure measurementsystem shall include associated electronics and readout devicesto display the resulting pressure reading.6.1.3 A thermostatically controlled heater shall be used
34、tomaintain the test chamber at 37.8 C 6 0.1 C (100 F 60.2 F) for the duration of the vapor pressure measurement.6.1.4 A platinum resistance thermometer shall be used formeasuring the temperature of the test chamber with a resolu-tion of 0.1 C (0.2 F) and an accuracy of 0.1 C (0.2 F).6.1.5 The vapor
35、pressure apparatus shall have provisions forintroduction of the test specimen into an evacuated testchamber, or into a test chamber by a moveable piston, and forthe cleaning or purging of the chamber following or precedingthe test.6.2 Vacuum Pump, capable of reducing the pressure in thetest chamber
36、to less than 0.01 kPa (0.001 psi) absolute.6.3 Syringe, (optional, depending on sample introductionmechanism employed with each instrument) gas-tight, 1 mL to5Available from Energy Institute, 61 New Cavendish St., London, W1G 7AR,U.K., http:/www.energyinst.org.D5191 18220 mL capacity with a 61 % or
37、better accuracy and a 61%orbetter precision. If a syringe is used to measure the samplevolume, the capacity of the syringe should not exceed twotimes the volume of the test specimen being dispensed.6.4 Iced Water Bath, Refrigerator, or Air Bath, for chillingthe samples and syringe to temperatures be
38、tween 0 C to 1 C(32 F to 34 F).6.5 Pressure Measuring Device, capable of measuring localstation pressure with an accuracy of 0.20 kPa (0.03 psi), orbetter, at the same elevation relative to sea level as theapparatus in the laboratory.6.5.1 When a mercury barometer is not used as the pressuremeasurin
39、g device, the calibration of the pressure measuringdevice employed shall be periodically checked (with traceabil-ity to a nationally recognized standard) to ensure that thedevice remains within the required accuracy specified in 6.5.6.6 McLeod Vacuum Gage or Calibrated Electronic VacuumMeasuring Dev
40、ice for Calibration, to cover at least the rangefrom 0.01 kPa to 0.67 kPa (0.1 mm Hg to 5 mm Hg). Thecalibration of the electronic vacuum measuring device shall beregularly verified in accordance with the annex section onVacuum Sensors (A6.3) of Test Method D2892.7. Reagents and Materials7.1 Purity
41、of ReagentsUse chemicals of at least 99 %purity for verification of instrument performance (see Section11). Unless otherwise indicated, it is intended that all reagentsconform to the specifications of the Committee on AnalyticalReagents of the American Chemical Society where suchspecifications are a
42、vailable.6Lower purities can be used,provided it is first ascertained that the reagent is of sufficientpurity to permit its use without lessening the accuracy of thedetermination.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 for verificationo
43、f instrument performance (see Section 11), based on thereference fuels analyzed in the 2003 interlaboratory study(ILS)2(see Table 1) and 2014 interlaboratory study (ILS)7(seeTable 2). Such reference fuels are not to be used for instrumentcalibration. Table 1 and Table 2 identify the accepted referen
44、cevalue (ARV) and uncertainty limits, as well as the acceptabletesting range for each of the reference fuels listed.NOTE 6Verification fluids reported by 28 of the 29 D5191 data setparticipants in the 2003 ILS2included the following (with number of datasets identified in parenthesis): 2,2-dimethylbu
45、tane (18), cyclopentane (5),pentane (2), 2,3-dimethylbutane (1), 3-methylpentane (1), and methanol(1).7.2 Cyclopentane, (WarningCyclopentane is flammableand a health hazard).7.3 2,2-Dimethylbutane, (Warning2,2-dimethylbutane isflammable and a health hazard).7.4 2,3-Dimethylbutane, (Warning2,3-dimeth
46、ylbutane isflammable and a health hazard).7.5 Methanol, (WarningMethanol is flammable and ahealth hazard).7.6 2-Methylpentane, (Warning2-methylpentane is flam-mable and a health hazard).7.7 Pentane, (WarningPentane is flammable and a healthhazard).7.8 Toluene, (WarningToluene is flammable and a heal
47、thhazard).8. Sampling8.1 General Requirements:8.1.1 The extreme sensitivity of vapor pressure measure-ments to losses through evaporation and the resulting changesin composition is such as to require the utmost precaution andthe most meticulous care in the drawing and handling ofsamples.8.1.2 Obtain
48、 samples and test specimens in accordance withPractice D4057, except do not use the “Sampling by WaterDisplacement” section for fuels containing oxygenates. Useeither 250 mL or 1 L (1 qt) sized containers filled between70 % and 80 % with sample.6Reagent Chemicals, American Chemical Society Specifica
49、tions, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.7Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D02-1805. ContactASTM CustomerService at serviceastm.org.TABLE 1 Accepted Reference Value (AR
