1、Designation: D5191 15Standard 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 (see Note 1). This test method is suitablefor testing samples with boiling points above 0 C (32 F)
4、 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 the sample.NOTE 1An interlaboratory study was conducte
5、d in 2008 involving 11different laboratories submitting 15 data sets and 15 different samples ofethanol-fuel blends containing 25 volume %, 50 volume %, and 75volume % ethanol. The results indicated that the repeatability limits ofthese samples are with in the published repeatability of this test me
6、thod.on this basis, it can be concluded that D5191 is applicable to ethanol-fuelblends such as Ed75 and Ed85 (Specification D5798) and other ethanol-fuel blends with greater than 10 v% ethanol. See ASTM RR: D021694filed with ASTM for supporting data.2NOTE 2Samples can also be tested at other vapor-t
7、o-liquid ratios,temperatures, and pressures, but the precision and bias statements need notapply.NOTE 3The interlaboratory studies conducted in 1988, 1991, and2003 to determine the precision statements in Test Method D5191 did notinclude any crude oil in the sample sets. Test Method D6377, as well a
8、sIP 481, have been shown to be suitable for vapor pressure measurementsof crude oils.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 no
9、t been determined(see Note 15).1.2 This test method is suitable for calculation 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
10、 obtained on the same materialwhen tested by Test Method D4953.1.3 The values stated in SI units are regarded as standard.The inch-pound units given in parentheses are provided forinformation only.1.4 WARNINGMercury has been designated by manyregulatory agencies as a hazardous material that can caus
11、ecentral nervous system, kidney and liver damage. Mercury, orits vapor, may be hazardous to health and corrosive tomaterials. Caution should be taken when handling mercury andmercury containing products. See the applicable product Ma-terial Safety Data Sheet (MSDS) for details and EPAs website http:
12、/www.epa.gov/mercury/faq.htm - for additional infor-mation. Users should be aware that selling mercury and/ormercury containing products into your state or country may beprohibited by law.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is
13、theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specific safetywarning statements, see 7.2 through 7.8.2. Referenced Documents2.1 ASTM Standards:3D2892 Test Method for Di
14、stillation of Crude Petroleum(15-Theoretical Plate Column)D4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4953 Test Method for Vapor Pressure of Gasoline andGasoline-Oxygenate Blends (Dry Method)D5798 Specification for Ethanol Fuel Blends for Flexible-Fuel Automotive Spark-Igni
15、tion EnginesD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate Analytical1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.08 on Vo
16、latility.Current edition approved Oct. 1, 2015. Published October 2015. Originallyapproved in 1991. Last previous edition approved in 2013 as D5191 13. DOI:10.1520/D5191-15.2Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D02-169
17、4.3For 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.*A Summary of Changes section appears at the end of this st
18、andardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1Measurement System PerformanceD6377 Test Method for Determination of Vapor Pressure ofCrude Oil: VPCRx(Expansion Method)D6378 Test Method for Determination of Vapor Pressure(VPX) o
19、f Petroleum Products, Hydrocarbons, andHydrocarbon-Oxygenate Mixtures (Triple ExpansionMethod)D7717 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 Pre
20、ssure (ASVP) of Crude Oil43. Terminology3.1 Definitions:3.1.1 fuel ethanol (Ed75Ed85), nblend of ethanol 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 o
21、f the air-free sample. It is calculated from the total vapor pressure of thesample by subtracting out 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 i
22、s expected to be equivalentto the value obtained on the sample by Test Method D4953,Procedure A.3.2.3 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.
23、1 DVPEdry vapor pressure equivalent3.3.2 Ptottotal vapor pressure4. Summary of Test Method4.1 A known 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 introduct
24、ion, the internalvolume of which is five times that of the total test specimenintroduced into the chamber. 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 meas
25、ured using a pressuretransducer sensor and indicator. Only total pressure measure-ments (sum of the 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 measu
26、red total vapor pressure is converted to a dryvapor pressure equivalent (DVPE) by use of a correlationequation (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 regu
27、lated by various government agencies.5.3 Specifications for volatile petroleum products generallyinclude 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 mLto 10 mL), and requiresabout 7
28、 min to complete the test.6. Apparatus6.1 Vapor Pressure ApparatusThe type of apparatus suit-able for use in this test method employs a small volume testchamber incorporating a transducer for pressure measurementsand associated equipment for thermostatically controlling thechamber temperature and fo
29、r evacuating the test chamber priorto sample introduction or expanding the volume after sampleintroduction by a moveable piston.6.1.1 The test chamber shall be designed to contain between5 and 50 mLof liquid and vapor and be capable of maintaininga vapor-to-liquid ratio between 3.95 to 1.00 and 4.05
30、 to 1.00.NOTE 4The test chamber employed by the instruments used ingenerating the precision and 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 ap
31、ply.6.1.2 The pressure transducer shall have a minimum opera-tional range from 0 kPa to 177 kPa (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
32、display the resulting pressure reading.6.1.3 A thermostatically controlled heater shall be used 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 te
33、st 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 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 foll
34、owing or precedingthe test.6.2 Vacuum Pump, capable of reducing the pressure in thetest chamber 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 to20 mL capacity with a 61 % or better accuracy
35、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.4Available from the Energy Institute, 61 New Cavendish St., London,WIG 7AR,U.K.D5191 1526.4 Iced Water Bath, Refrigera
36、tor, or Air Bath, for chillingthe samples and syringe to temperatures between 0 C to 1 C(32F 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 labora
37、tory.6.5.1 When a mercury barometer is not used as the pressuremeasuring 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
38、6.5.6.6 McLeod Vacuum Gage or Calibrated Electronic VacuumMeasuring Device 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 S
39、ensors (A6.3) of Test Method D2892.7. Reagents and Materials7.1 Purity 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 AnalyticalR
40、eagents of the American Chemical Society where suchspecifications are available.5Lower 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
41、, and 7.8(blended by mass with pentane) are suggested for verificationof instrument performance (see Section 11), based on thereference fuels analyzed in the 2003 interlaboratory study(ILS)6(see Table 1) and 2014 interlaboratory study (ILS)7(seeTable 2). Such reference fuels are not to be used for i
42、nstrumentcalibration. Table 1 and Table 2 identify the accepted referencevalue (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 ILS6included the follow
43、ing (with number of datasets identified in parenthesis): 2,2-dimethylbutane (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 isfl
44、ammable and a health hazard).7.4 2,3-Dimethylbutane, (Warning2,3-dimethylbutane 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 a
45、nd a healthhazard).7.8 Toluene, (WarningToluene is flammable and a healthhazard).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
46、most meticulous care in the drawing and handling ofsamples.8.1.2 Obtain 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 8
47、0 % with sample. For best testing precision(reproducibility), it is recommended that 1 L sized containersbe used.NOTE 7The current precision statements were derived from the 2003ILS6using samples in 250 mL and 1 L (1 qt) clear glass containers.However, samples in containers of other sizes, as prescr
48、ibed in PracticeD4057, may be used with the same ullage requirement if it is recognizedthat the precision can be affected. The differences in precision resultsobtained from 250 mL and 1 L containers were found to be statistically5Reagent Chemicals, American Chemical Society Specifications, AmericanC
49、hemical 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.6Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D02-1619. ContactASTM CustomerService at serviceastm.org.7Supporting data have been filed at ASTM Internati
