1、Designation: D 5190 01An American National StandardStandard Test Method forVapor Pressure of Petroleum Products (Automatic Method)1This standard is issued under the fixed designation D 5190; the number immediately following the designation indicates the year oforiginal adoption or, in the case of re
2、vision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the determination of the totalpressure of air-containing, volatile, petr
3、oleum products. Thistest method is suitable for testing samples with boiling pointsabove 0C (32F) that exert a vapor pressure between 7 and172 kPa (1 and 25 psi) at 37.8C (100F) at a vapor-to-liquidratio of 4:1. This test method is suitable for testing gasolinesamples that contain oxygenates. No acc
4、ount is made ofdissolved water in the sample.1.1.1 Some gasoline-oxygenate blends may show a hazewhen cooled to 0 to 1C. If a haze is observed in 8.5, it shallbe indicated in the reporting of results. The precision and biasstatements for hazy samples have not been determined (seeNote 8).1.2 This tes
5、t method is suitable for the calculation of a dryvapor pressure equivalent (DVPE) by means of a correlationequation (see 13.1). The calculated DVPE very closely ap-proximates the dry vapor pressure that would be obtained onthe same material when tested in accordance with Test MethodD 4953.1.3 The va
6、lues stated in SI units are to be regarded as thestandard. The inch-pound units given in parentheses areprovided for information only.1.4 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 esta
7、blish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specific hazardstatements, see 7.3 through 7.5 and 9.2.2. Referenced Documents2.1 ASTM Standards:D 4057 Practice for Manual Sampling of Petroleum andPetroleum Products2D 4953 T
8、est Method for Vapor Pressure of Gasoline andGasoline-Oxygenate Blends (Dry Method)2D 5191 Test Method for Vapor Pressure of Petroleum Prod-ucts (Mini Method)22.2 ASTM Adjuncts:Detailed Drawings for Automatic Vapor Pressure Instru-ment33. Terminology3.1 Definitions of Terms Specific to This Standard
9、:3.1.1 total pressure, nthe observed pressure measured inthe experiment, that is, the sum of the partial pressure of thesample and the partial pressure of the dissolved air.3.1.2 dry vapor pressure equivalent (DVPE), na valuecalculated by a correlation equation (see 13.1) from the totalpressure.3.1.
10、2.1 DiscussionThe DVPE is expected to be equivalentto the value obtained on the sample by Test Method D 4953,Procedure A.4. Summary of Test Method4.1 The chilled sample cup of the automatic vapor pressureinstrument is filled with chilled sample and is coupled to theinstrument inlet fitting. The samp
11、le is then automaticallyforced from the sample chamber to the expansion chamberwhere it is held until thermal equilibrium at 37.8C (100F) isreached. In this process the sample is expanded to five times itsvolume (4:1 vapor-to-liquid ratio). The vapor pressure ismeasured by a pressure transducer.4.2
12、The measured vapor pressure is automatically convertedto a DVPE value by the instrument. A correction to this valueis necessary to account for the observed bias between the testresult and that obtained by Test Method D 4953.5. Significance and Use5.1 Vapor pressure is an important physical property
13、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 generallyinclude vapor pressure limits to ensure products of suitablevolatility performance.1This test method is under the
14、 jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.08 on Volatility.Current edition approved May 10, 2001. Published July 2001. Originallypublished as D 5190 91. Last previous edition D 5190 99.2Annual Book of ASTM Standards, V
15、ol 05.02.3Available from ASTM Headquarters. Order PCN 12-50014012.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.4 This test method is more precise than Test Method
16、D 4953.6. Apparatus6.1 Automatic Vapor Pressure Instrument,4the essentialfeatures describing the sample flow and operation of theautomatic vapor pressure instrument is provided in Annex A1.Critical elements of the apparatus are included as follows:6.1.1 Pressure Transducer, capable of operating in t
17、he rangefrom 0 to 172 kPa (0 to 25 psi) with the resolution of 0.1 kPa(0.01 psi) and a minimum accuracy of 60.7 kPa (60.10 psi).6.1.2 Thermostatically Controlled Heater, capable of main-taining an oil bath surrounding the test chambers at37.8 6 0.1C (100 6 0.2F) for the duration of the test.6.1.3 Sa
18、mple Cup, capable of holding up to 125 mL.6.2 Iced-Water Bath or Air Bath, for chilling the testsamples and sample cup to temperatures between 0 to 1C (32to 34F).7. Reagents and Materials7.1 Purity of ReagentsChemicals of at least 98 % purityshall be used in the calibration procedure (see Section 10
19、).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 available.5Lower purities may be used,provided it is first ascertained that the reagent is of sufficientpur
20、ity to permit its use without lessening the accuracy of thedetermination.NOTE 1Although higher purity chemicals in the 99 + % range arepreferred for use in calibrations, the precision and bias statements (seeSection 15) were derived with the minimum purity level stated in 7.1.7.2 2,2-Dimethylbutane.
21、7.3 n-Hexane,(Warning2,2-Dimethylbutane, n-hexaneis extremely flammable, harmful if inhaled. Skin irritant onrepeated contact. Aspiration hazard).7.4 n-Pentane,(Warning2,2-Dimethylbutane, n-pentaneis extremely flammable, harmful if inhaled. Skin irritant onrepeated contact. Aspiration hazard).7.5 To
22、luene,(Warning2,2-Dimethylbutane, toluene isextremely flammable, harmful if inhaled. Skin irritant onrepeated contact. Aspiration hazard).8. Sampling8.1 General Procedures:8.1.1 The extreme sensitivity of vapor pressure measure-ments to losses through evaporation and the resulting change incompositi
23、on is such as to require the utmost precaution and themost meticulous care in the drawing and handling of samples.8.1.2 Obtain a sample and test specimen in accordance withPractice D 4057, except do not use “Sampling by WaterDisplacement” for fuels containing oxygenates. Use a 1-L(1-qt) size contain
24、er filled between 70 and 80 % with thesample.NOTE 2The present precision statement was derived using thesamples in 1-L (1-qt) containers. However, the samples in containers ofother sizes, as prescribed in Practice D 4057 can be used, with the sameullage requirement, if it is recognized that the prec
25、ision can be affected.8.1.3 In the case of referee testing, the 1-L (1-qt) samplecontainer is mandatory.8.1.4 Perform the vapor pressure determination on the firsttest specimen withdrawn from a sample container. Do not usethe remaining sample in the container for a second vaporpressure determination
26、. If a second determination is necessary,obtain a new sample.8.1.5 Protect the samples from excessive temperatures priorto testing. This can be accomplished by storage in an appro-priate ice bath or refrigerator.8.1.6 Do not test samples stored in leaky containers. If leaksare detected, discard and
27、obtain a new sample.8.2 Sampling Handling Temperature Cool the samplecontainer and contents in an ice bath or refrigerator to betweem0 and 1C (32 and 34F) prior to opening the sample container.Allow sufficient time to reach this temperature. Verify thesample temperature by direct measurement of the
28、temperatureof a similar liquid in a similar container placed in the coolingbath or refrigerator at the same time as the sample.8.3 Verification of Sample Container FillingWith thesample at a temperature of 0 to 1C, take the container from thecooling bath or refrigerator and wipe dry with absorbentma
29、terial. If the container is not transparent, unseal it and usinga suitable gage, confirm that the sample volume equals 70 to80 % of the container capacity (see Note 3). If the sample iscontained in a transparent glass container, verify that thecontainer is 70 to 80 % full by suitable means (see Note
30、 3).NOTE 3For non-transparent containers, one way to confirm that thesample volume equals 70 to 80 % of the container capacity is to use adipstick that has been pre-marked to indicate the 70 and 80 % containercapacities. The dipstick should be of such material that it shows wettingafter being immers
31、ed and withdrawn from the sample. To confirm thesample volume, insert the dipstick into the sample container so that ittouches the bottom of the container at a perpendicular angle, beforeremoving the dipstick. For transparent containers, using a marked ruler orcomparing the sample container to a lik
32、e container that has the 70 and80 % levels clearly marked, has been found suitable.8.3.1 Discard the sample if the container is filled to less than70 volume % of the container capacity.8.3.2 If the container is more than 80 volume % full, pourout enough sample to bring the container contents within
33、70 to80 volume % range. Do not return any sample to the containeronce it has been withdrawn.8.3.3 Reseal the container, if necessary, and return thesample container to the cooling bath or refrigerator.8.4 Air Saturation of the Sample in the Sample Container:8.4.1 Transparent Containers OnlySince 8.3
34、 does notrequire that the sample container be opened to verify thesample capacity, it is necessary to unseal the cap momentarily4The following instrument has been found suitable by interlaboratory coopera-tive testing: Vapor Pressure Instrument, available from Southwest Research Insti-tute, San Anto
35、nio, Texas.5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States
36、 Pharmacopeialand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.D5190012before resealing it, so that samples in transparent containers aretreated the same as samples in non-transparent containers.8.4.2 With the sample again at a temperature of 0 to 1C,take the containe
37、r from the cooling bath or refrigerator, wipe itdry with an absorbent material, remove the cap momentarily,taking care that no water enters, reseal and shake vigorously.Return it to the bath or refrigerator for a minimum of 2 min.8.4.3 Repeat 8.4.2 twice more. Return the sample to the bathor refrige
38、rator until the beginning of the procedure.8.5 Verification of Single Phase SamplesAfter drawing atest specimen into the sample cup and coupling the cup to theinstrument for analysis, check the remaining sample for phaseseparation. If the sample is contained in a glass container, thisobservation can
39、 be made prior to sample transfer. If the sampleis contained in a non-transparent container, mix the samplethoroughly and immediately pour a portion of the remainingsample into a clear glass container and observe for evidence ofphase separation. A hazy appearance is to be carefully distin-guished fr
40、om separation into two distinct phases. The hazyappearance shall not be considered grounds for rejection of thefuel. If a second phase is observed, discard the test and thesample. Hazy samples may be analyzed (see Report section).9. Preparation of Apparatus9.1 Prepare the automatic vapor pressure in
41、strument foroperation in accordance with the manufacturers instructions.9.2 Clean and dry the sample cup prior to use.(WarningDo not analyze a water saturated sample. If wateris accidentally introduced into the instrument, analyze a drysample six to ten times until all the water has been flushed fro
42、mthe instrument and a repeatability of 61.4 kPa (0.20 psi) isobtained for duplicate runs.)9.3 Chill the stoppered, dry sample cup to between 0 andlC (32 and 34F) in a refrigerator or ice bath before transfer-ring the sample into the cup. Avoid water contamination of thesample cup by sealing the samp
43、le cup during the coolingprocess.9.4 Prior to starting the measurement, check that the tem-perature of the test chamber is within the required rangespecified by the manufacturer of the instrument.10. Calibration10.1 Pressure Transducer:10.1.1 Calibrate the pressure transducer at least every 30days o
44、r when needed as indicated from the performancechecks. The calibration of the transducer is accomplished usingthree reference materials to cover the range above and below34 kPa (5.0 psi).NOTE 4The instrument manufacturer provides an alternative calibra-tion procedure using two reference points, zero
45、 pressure (0.1 kPa) andthe ambient barometric pressure. However, since this procedure was notincluded in the interlaboratory program, the precision and bias can beaffected by its use.10.1.2 Load n-hexane into the instrument, obtain a vaporpressure reading and then adjust the zero potentiometer for t
46、hetransducer to obtain a calibration value of 5.00 6 0.02 on thedigital meter display.NOTE 5The target calibration values used in this section are specificto the automatic vapor pressure instrument4evaluated in the 1988interlaboratory cooperative program.6These calibration values do notnecessarily c
47、orrespond to the total vapor pressures or the dry vaporpressures (see Test Method D 4953) reported for the reference calibrationmaterials, but rather are values that the instrument manufacturer suggestsusing to produce a dry vapor pressure equivalent reading on the digitaldisplay.10.1.3 Load n-penta
48、ne into the instrument, obtain a pressurereading on the digital meter, and then adjust the transducerspan potentiometer to achieve a value of 15.40 6 0.05 on thedigital meter.10.1.4 Repeat 10.1.2 and 10.1.3 until the appropriate cali-bration values are displayed without making further adjust-ments.1
49、0.1.5 Load the instrument with 2,2-dimethylbutane andobtain a pressure reading. If the digital display reads 9.90 60.1, then the instrument is calibrated; if not, then repeat theabove procedure until a satisfactory calibration is achieved.10.1.6 For calibration of the range below 34 kPa (5.0 psi),perform the steps in 10.1.2 to 10.1.4, replacing n-hexane (34kPa) in step 10.1.2 with toluene (7 kPa), and replacingn-pentane (106 kPa) in step 10.1.3 with n-hexane (34 kPa).10.2 TemperatureAt least every six months, check thecalibration of the thermom
