1、Designation: D4953 15Standard 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 revision, the year o
2、f 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. Scope*1.1 This test method covers and is applicable to gasolinesand gasoline-oxygenate blends with a vapor pressure rangefrom
3、 35 kPa to 100 kPa (5 psi to 15 psi) (see Note 2). This testmethod, a modification of Test Method D323 (Reid Method),provides two procedures to determine the vapor pressure (Note1) of gasoline and gasoline-oxygenate blends.NOTE 1Because the external atmospheric pressure is counteracted bythe atmosph
4、eric pressure initially present in the air chamber, this vaporpressure is an absolute pressure at 37.8 C (100 F) in kilopascals(pounds-force per square inch). This vapor pressure differs from the truevapor pressure of the sample due to some small vaporization of the sampleand air in the confined spa
5、ce.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 a0 kPa to 200 kPa (
6、0 psi to 30 psi) gauge as specified in the annex of TestMethod D323.1.2 Some gasoline-oxygenate blends may show a haze whencooled to 0 C to 1 C. 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
7、(seeNote 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 estab
8、lish 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 Meth
9、od)D4057 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) (Withdrawn 2012)3D5191 Test Method for Vapor Pressure of Petroleum Prod-uct
10、s (Mini Method)E1 Specification 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 pres
11、sure.3.1.3 dry method, 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 defi
12、ned correlation equation, that is expected to becomparable to the vapor pressure value obtained by TestMethod D4953, Procedure A.3.1.5 oxygenate, noxygen-containing ashless organiccompound, such as an alcohol or ether, which may be used asa fuel or fuel supplement. D41753.1.6 vapor pressure, npressu
13、re exerted by the vapor of aliquid when in equilibrium with the liquid D41751This test method is under the jurisdiction of Committee D02 on PetroleumProducts, Liquid Fuels, and Lubricants and is the direct responsibility of Subcom-mittee D02.08 on Volatility.Current edition approved June 1, 2015. Pu
14、blished June 2015. Originallyapproved in 1989. Last previous edition approved in 2012 as D4953 06 (2012).DOI: 10.1520/D4953-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information
15、, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken,
16、PA 19428-2959. United States13.2 Abbreviations:3.2.1 DVPE, ndry vapor 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 37.8 C (100 F). The apparatus is immersed in abath at 37.8 C
17、(100 F) until a constant pressure is observed.The pressure reading, suitably 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 are
18、maintained completely free of water. Procedure B utilizes asemi-automatic 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 canb
19、e used with this procedure. The interior surfaces of the liquidand vapor 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 operati
20、ng conditions.For example, vapor pressure is a factor in determining whethera 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 pro
21、ducts of suitable volatilityperformance.NOTE 3Vapor pressure of fuels is 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 thos
22、e forProcedure A and described in Annex A1. External fittings andfeatures 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 app
23、lies to both Procedure A and B.7.2 The extreme sensitivity of vapor pressure 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
24、Practice D4057 except forfuels containing oxygenates where the Water DisplacementProcedure 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 wi
25、th sample.7.4.2 The present precision statement has been derivedusing samples 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 con
26、tainer shall bemandatory.7.5 Hazards:7.5.1 The vapor pressure determination 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 fro
27、m excessive heat priorto testing.7.5.3 Samples in leaky containers shall not be tested.Discard and obtain a new sample.7.6 Sample Handling TemperatureIn all cases, the samplecontainer and contents shall be cooled to 0 C to 1 C (32 F to34 F) before the container is opened. Sufficient time to reachthi
28、s temperature shall be assured by direct measurement of thetemperature of a similar 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 Contai
29、ner FillingWith thesample at a temperature of 0 C to 1 C, take the containerfrom the cooling bath or refrigerator and wipe dry withabsorbent material. If the container is not transparent, unseal it,and using a suitable gauge, confirm that the sample volumeequals 70 % to 80 % of the container capacit
30、y (see Note 4). Ifthe sample is contained in a transparent glass container, verifythat the container is 70 % to 80 % full by suitable means (seeNote 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 tha
31、t has been pre-marked to indicate the 70 % and 80 % containercapacities. The dipstick should 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 con
32、tainer at a perpendicular angle, beforeremoving the dipstick. For transparent containers, using a marked ruler orby comparing the sample container to a like container which has the 70 %and 80 % levels clearly marked, has been found suitable.8.2.1 Discard the sample if its volume is less than 70 % of
33、the container capacity.8.2.2 If the container is more than 80 % full, pour outenough sample 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
34、the cooling bath.8.3 Air Saturation of the Sample in Sample Container:D4953 1528.3.1 Transparent 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 conta
35、iners are treated thesame as samples in non-transparent containers.8.3.2 With the sample again at a temperature of 0 C to1 C, take the container from the cooling bath or refrigerator,wipe it dry with an absorbent material, remove the capmomentarily, taking care that no water enters, reseal, and shak
36、evigorously. Return it to the cooling bath or refrigerator for aminimum of 2 min.8.3.3 Repeat 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 i
37、n a refrigerator or cooling bath forsufficient time to allow the chamber and the transfer tube toreach a temperature of 0 C to 1 C (32 F to 34 F). Keep theliquid chamber upright and not immersed over the top of thecoupling threads. (WarningThe transfer connection must bekept completely dry during co
38、oling. This can be accomplishedby placing the transfer connection in a water tight plastic bag.)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.
39、 Make surethat the vent hole in the vapor chamber connection is alsosecurely closed. (WarningMaking 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.
40、)NOTE 5For some Test Method D323 apparatus, a Number 6.5 rubberstopper has been found satisfactory. 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
41、 the conditioning period. A third alternative isto utilize a cap threaded to match the threads of 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 sampl
42、e must be kept completely freeof water.8.5.2 Immerse the vapor chamber in a water bath main-tained at 37.8 C 6 0.1 C (100 F 6 0.2 F) for not less than20 min. The top of the vapor chamber must be at least 25 mm(1 in.) below the surface of the water (Procedure A). (InProcedure B the vapor chamber lies
43、 horizontally, completelyimmersed in the water bath.) Do not remove the vapor chamberfrom the water bath until the liquid chamber has been filledwith sample as described in 9.1.9. Procedure9.1 Sample TransferRemove the sample from the coolingbath, dry the exterior of the container with absorbent mat
44、erial,uncap, and insert the chilled transfer tube (see Fig. 1). Removethe liquid chamber from the cooling 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 cham
45、ber is uprightwith the end of the transfer tube approximately 6 mm (0.25 in.)from the bottom of the liquid 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 m
46、ade forsuitable containment and disposal of the overflowing sample toavoid fire hazard.)9.2 Assembly of 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 bet
47、ween the vaporchamber and the liquid chamber. Remove the closure from thevapor chamber and couple the 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
48、chamberwithout undue movement that could promote exchange ofroom temperature air with the 37.8 C (100 F) 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 dis
49、connect the spiral tubing at the quick action disconnectafter removing from the water bath and before making 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 C 6 0.1 C (100 F 6 0.2 F), in an inclined position
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