1、Designation: D4953 06 (Reapproved 2012)Standard Test Method forVapor Pressure of Gasoline and Gasoline-Oxygenate Blends(Dry Method)1This standard is issued under the fixed designation D4953; 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 () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers and is applicable to gasolinesand gasoline-oxygenate blends with a vapor p
3、ressure rangefrom 35 to 100 kPa (5 to 15 psi) (see Note 2). This test method,a modification of Test Method D323 (Reid Method), providestwo procedures to determine the vapor pressure (Note 1)ofgasoline and gasoline-oxygenate blends.NOTE 1Because the external atmospheric pressure is counteracted bythe
4、 atmospheric pressure initially present in the air chamber, this vaporpressure is an absolute pressure at 37.8C (100F) in kilopascals (pounds-force per square inch). This vapor pressure differs from the true vaporpressure of the sample due to some small vaporization of the sample andair in the confi
5、ned space.NOTE 2Vapor pressure of gasoline or gasoline-oxygenate blendsbelow 35 kPa (5 psi) or greater than 100 kPa (15 psi) can be determinedwith this test method but the precision and bias (Section 11) do not apply.For materials with a vapor pressure greater than 100 kPa (15 psi), use a 0to 200 kP
6、a (0 to 30 psi) gauge as specified in the annex of Test MethodD323.1.2 Some gasoline-oxygenate blends may show a haze whencooled to 0 to 1C. If a haze is observed in 9.4, it shall beindicated in the reporting of results. The precision and biasstatements for hazy samples have not been determined (see
7、Note 7).1.3 The values stated in SI units are to be regarded asstandard. The values given in parentheses are for informationonly.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 establish
8、 appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific warningsare given in 7.5, 8.4.1, 8.5.1, 9.1, A1.1, and A1.1.3.2. Referenced Documents2.1 ASTM Standards:2D323 Test Method for Vapor Pressure of Petroleum Products(Reid Method)D
9、4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4175 Terminology Relating to Petroleum, PetroleumProducts, and LubricantsD5190 Test Method for Vapor Pressure of Petroleum Prod-ucts (Automatic Method)D5191 Test Method for Vapor Pressure of Petroleum Prod-ucts (Mini Method)E1 Spec
10、ification for ASTM Liquid-in-Glass Thermometers3. Terminology3.1 Definitions:3.1.1 Bourdon spring gauge, npressure measuring devicethat employs a bourdon tube connected to an indicator.3.1.2 Bourdon tube, nflattened metal tube bent to a curvethat straightens under internal pressure.3.1.3 dry method,
11、 nin vapor pressure methods, a specificempirical test method (D4953) for measuring the vapor pres-sure of gasoline and other volatile products in which contact ofthe test specimen with water is not allowed.3.1.4 dry vapor pressure equivalent (DVPE), nvalue cal-culated by a defined correlation equati
12、on, that is expected to becomparable to the vapor pressure value obtained by TestMethod D4953, Procedure A.3.1.5 gasoline-oxygenate blend, nspark-ignition enginefuel consisting primarily of gasoline with one or more oxygen-ates.3.1.6 oxygenate, noxygen-containing ashless organiccompound, such as an
13、alcohol or ether, which may be used asa fuel or fuel supplement. D41751This test method is under the jurisdiction of Committee D02 on PetroleumProducts and Lubricants and is the direct responsibility of Subcommittee D02.08 onVolatility.Current edition approved Nov. 1, 2012. Published November 2012.
14、Originallyapproved in 1989. Last previous edition approved in 2006 as D495306. DOI:10.1520/D4953-06R12.2For 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
15、 Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.7 vapor pressure, npressure exerted by the vapor of aliquid when in equilibrium with the liquid D41753.2 Abbreviations:3.2.1 DVPE, ndry vapo
16、r pressure equivalent4. Summary of Test Method4.1 The liquid chamber of the vapor pressure apparatus isfilled with the chilled sample and connected to the vaporchamber at 37.8C (100F). The apparatus is immersed in abath at 37.8C (100F) until a constant pressure is observed.The pressure reading, suit
17、ably corrected, is reported as thevapor pressure.4.2 Procedure A utilizes the same apparatus and essentiallythe same procedure as Test Method D323 with the exceptionthat the interior surfaces of the liquid and vapor chambers aremaintained completely free of water. Procedure B utilizes asemi-automati
18、c apparatus with the liquid and vapor chambersidentical in volume to those in Procedure A. The apparatus issuspended in a horizontal bath and rotated while attainingequilibrium. Either a Bourdon gauge or pressure transducer canbe used with this procedure. The interior surfaces of the liquidand vapor
19、 chambers are maintained free of water.5. Significance and Use5.1 Vapor pressure is an important physical property ofliquid spark-ignition engine fuels. It provides an indication ofhow a fuel will perform under different operating conditions.For example, vapor pressure is a factor in determining whe
20、thera fuel will cause vapor lock at high ambient temperature or athigh altitude, or will provide easy starting at low ambienttemperature.5.2 Petroleum product specifications generally include va-por pressure limits to ensure products of suitable volatilityperformance.NOTE 3Vapor pressure of fuels is
21、 regulated by various governmentagencies.6. Apparatus6.1 The apparatus for Procedure A is described in AnnexA1.6.2 The essential dimensions and requirements for the liquidand vapor chamber for Procedure B are identical with those forProcedure A and described in Annex A1. External fittings andfeature
22、s will vary depending on whether a gauge or transduceris used and the provision for rotating the apparatus in the bath.Details of a commercially available unit are shown in AnnexA2.7. Handling of Test Samples7.1 This section applies to both Procedure A and B.7.2 The extreme sensitivity of vapor pres
23、sure measurementsto losses through evaporation is such as to require the utmostprecaution and the most meticulous care in handling ofsamples.7.3 Sampling shall be done in accordance with the ReidVapor Pressure section (10.3) of Practice D4057 except forfuels containing oxygenates where the Water Dis
24、placementProcedure section (10.3.1.8) of D4057 must not be used.7.4 Sample Container Size:7.4.1 The size of the sample container from which the vaporpressure sample is taken shall be 1 L (1 qt). It shall be 70 to80 % filled with sample.7.4.2 The present precision statement has been derivedusing samp
25、les in 1-L (1-qt) containers. Samples taken incontainers of other sizes as prescribed in Practice D4057 can beused if it is recognized that the precision can be affected. In thecase of referee testing the 1-L (1-qt) sample container shall bemandatory.7.5 Hazards:7.5.1 The vapor pressure determinatio
26、n shall be the first testwithdrawn from the sample container. The remaining sample inthe container cannot be used for a second vapor pressuredetermination. If necessary, obtain a new sample.7.5.2 Samples shall be protected from excessive heat priorto testing.7.5.3 Samples in leaky containers shall n
27、ot be tested.Discard and obtain a new sample.7.6 Sample Handling TemperatureIn all cases, the samplecontainer and contents shall be cooled to 0 to 1C (32 to 34F)before the container is opened. Sufficient time to reach thistemperature shall be assured by direct measurement of thetemperature of a simi
28、lar liquid in a like container placed in thecooling bath at the same time as the sample. See A1.3.1.8. Preparation of Apparatus8.1 This section applies to both Procedure A and ProcedureB.8.2 Verification of Sample Container FillingWith thesample at a temperature of 0 to 1C, take the container from t
29、hecooling bath or refrigerator and wipe dry with absorbentmaterial. If the container is not transparent, unseal it, and usinga suitable gauge, confirm that the sample volume equals 70 to80 % of the container capacity (see Note 4). If the sample iscontained in a transparent glass container, verify th
30、at thecontainer is 70 to 80 % full by suitable means (see Note 4).NOTE 4For 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 shou
31、ld be of such material that it shows wettingafter being immersed 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,
32、using a marked ruler orby comparing the sample container to a like container which has the 70and 80 % levels clearly marked, has been found suitable.8.2.1 Discard the sample if its volume is less than 70 % ofthe container capacity.8.2.2 If the container is more than 80 % full, pour outenough sample
33、to bring the container contents within 70 to80 % range. Under no circumstance return any of the pouredout sample to the container.8.2.3 Reseal the container, if necessary, and return thesample container to the cooling bath.8.3 Air Saturation of the Sample in Sample Container:D4953 06 (2012)28.3.1 Tr
34、ansparent Containers OnlySince 8.2 does notrequire that the sample be opened to verify the sample capacity,it is necessary to unseal the cap momentarily before resealingit, so that the samples in transparent containers are treated thesame as samples in non-transparent containers.8.3.2 With the sampl
35、e again at a temperature of 0 to 1C,take the container 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 cooling bath or refrigerator for a minimum of2 min.8.3.3 Rep
36、eat 8.3.2 twice more. Return the sample to thecooling bath until the beginning of the procedure.8.4 Preparation of Liquid Chamber:8.4.1 Place the stoppered or closed liquid chamber and thesample transfer tube in a refrigerator or cooling bath forsufficient time to allow the chamber and the transfer
37、tube toreach a temperature of 0 to 1C (32 to 34F). Keep the liquidchamber upright and not immersed over the top of the couplingthreads. (WarningThe transfer connection must be keptcompletely dry during cooling. This can be accomplished byplacing the transfer connection in a water tight plastic bag.)
38、8.5 Preparation of the Vapor Chamber:8.5.1 Connect the gauge or pressure transducer to the vaporchamber and make a water tight closure of the lower openingof the chamber where the liquid chamber attaches. Make surethat the vent hole in the vapor chamber connection is alsosecurely closed. (WarningMak
39、ing a water tight closure ofboth the liquid and vapor chambers is extremely important. Forsome samples containing oxygenated compounds, contact withwater can cause phase separation and invalidate results.)NOTE 5For some Test Method D323 apparatus, a Number 6.5 rubberstopper has been found satisfacto
40、ry. For the horizontal or Herzogapparatus, a Number 3 rubber stopper and a Number 000 cork in the venthole is satisfactory. Another procedure is to attach a spare liquid chamberto the vapor chamber during the conditioning period. A third alternative isto utilize a cap threaded to match the threads o
41、f the vapor chamber.Several apparatus manufacturers have indicated the intention to supplysuch caps for equipment. In any procedure used, the interior surfaces ofthe vapor pressure apparatus and the sample must be kept completely freeof water.8.5.2 Immerse the vapor chamber in a water bath main-tain
42、ed at 37.8 6 0.1C (100 6 0.2F) for not less than 20 min.The top of the vapor chamber must be at least 25 mm (1 in.)below the surface of the water (Procedure A). (In Procedure Bthe vapor chamber lies horizontally, completely immersed inthe water bath.) Do not remove the vapor chamber from thewater ba
43、th until the liquid chamber has been filled with sampleas described in 9.1.9. Procedure9.1 Sample TransferRemove the sample from the coolingbath, dry the exterior of the container with absorbent material,uncap, and insert the chilled transfer tube (see Fig. 1). Removethe liquid chamber from the cool
44、ing bath and, using anabsorbent material, dry the threaded top and place the chamberin an inverted position over the top of the transfer tube. Invertthe entire system rapidly so that the liquid chamber is uprightwith the end of the transfer tube approximately 6 mm (0.25 in.)from the bottom of the li
45、quid chamber. Fill the chamber tooverflowing. Withdraw the transfer tube from the liquid cham-ber while allowing the sample to continue flowing up tocomplete withdrawal. (WarningProvision shall be made forsuitable containment and disposal of the overflowing sample toavoid fire hazard.)9.2 Assembly o
46、f ApparatusImmediately remove the vaporchamber from the water bath and, as quickly as possible, drythe exterior of the chamber with absorbent material withparticular care given to the connection between the vaporchamber and the liquid chamber. Remove the closure from thevapor chamber and couple the
47、filled liquid chamber to thevapor chamber as quickly as possible without spillage. Whenthe vapor chamber is removed from the water bath and driedand the closure is removed, connect it to the liquid chamberwithout undue movement that could promote exchange ofroom temperature air with the 37.8C (100F)
48、 air in thechamber. Not more than 10 s should elapse between removingthe vapor chamber from the water bath and completion of thecoupling of the two chambers. With Procedure B it is necessaryto disconnect the spiral tubing at the quick action disconnectafter removing from the water bath and before ma
49、king theconnection to the vapor chamber.9.3 Introduction of the Apparatus into Bath:9.3.1 Procedure ATurn the assembled apparatus upsidedown and allow all the sample in the liquid chamber to draininto the vapor chamber. With the apparatus still inverted, shakeit vigorously eight times lengthwise. With the gauge end up,immerse the assembled apparatus in the bath, maintained at37.8 6 0.1C (100 6 0.2F), in an inclined position so that theconnection of the liquid and vapor chambers is below the waterlevel. Carefully examine for leaks. If no leaks
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