1、Designation: D1267 02 (Reapproved 2007)D1267 12Standard Test Method forGage Vapor Pressure of Liquefied Petroleum (LP) Gases(LP-Gas Method)1This standard is issued under the fixed designation D1267; the number immediately following the designation indicates the year oforiginal adoption or, in the ca
2、se of revision, 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. Scope Scope*1.1 This test method covers the determination of the gage vapor pressures of liquefied
3、petroleum gas products (WarningFlammable gas. Harmful when inhaled.) at temperatures of 37.8C (100F) up to and including a test temperature of 70C (158F).1.2 The values stated in acceptable metric SI units are to be regarded as the standard. The values given in parentheses are forinformation only.1.
4、3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. For specific hazar
5、dwarning statements, see 3.2.11.1 and Annex A2.2. Referenced Documents2.1 ASTM Standards:2D323 Test Method for Vapor Pressure of Petroleum Products (Reid Method)D1265 Practice for Sampling Liquefied Petroleum (LP) Gases, Manual MethodE1 Specification for ASTM Liquid-in-Glass Thermometers2.2 Institut
6、e of Petroleum Standard:IP 181 Sampling Petroleum Gases33. Terminology3.1 Definitions:3.1.1 vapor pressurethe pressure exerted by the vapor of a liquid when in equilibrium with the liquid.3.1 Definitions of Terms Specific to This Standard:Definitions:3.1.1 liquefied petroleum gasesgases, nnarrow boi
7、ling range hydrocarbon mixtures consisting chieflymainly of propane orpropylene, or both, (andWarningExtremely flammable. Harmful when inhaled.) butanes and butanes or butylenes, or both, inwhich the content of hydrocarbon compounds of higher boiling point than 0C (32F) is less than 5 % by liquid vo
8、lume, and whosegage vapor pressure at 37.8C (100F) is not greater than approximately 1550 kPa (225 psi).plus limited amounts of otherhydrocarbons and naturally occurring non-hydrocarbons.3.1.2 vapor pressure, nthe pressure exerted by the vapor of a liquid when in equilibrium with the liquid.4. Summa
9、ry of Test Method4.1 The test apparatus, consisting of two interconnected chambers and equipped with a suitable pressure gage, is purged witha portion of the sample which is then discarded. The apparatus is then filled completely with the portion of the sample to be tested.Thirty-three and one-third
10、 to forty volume percent of the sample content of the apparatus is immediately withdrawn to provideadequate free space for product expansion. The apparatus is then immersed in a water bath maintained at the standard testtemperature of 37.8C (100F) or, optionally, at some higher test temperature up t
11、o and including a test temperature of 70C(158F).1 This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee D02.H0 onLiquefied Petroleum Gas.Current edition approved May 1, 2007Nov. 1, 2012. Published June 2
12、007February 2013. Originally approved in 1953. Last previous edition approved in 20022007 asD1267D126702(2007).02. DOI: 10.1520/D1267-02R07. 10.1520/D1267-12.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of AS
13、TM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically p
14、ossible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standard
15、Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.2 The observed gage pressure at equilibrium, after correcting for gage error and correcting to a standard barometric pressure,is reported as the LPG Vapor Pressure at the selected test
16、 temperature.5. Significance and Use5.1 Information on the vapor pressures of liquefied petroleum gas products under temperature conditions from 37.8 to 70C (100to 158F) is pertinent to selection of properly designed storage vessels, shipping containers, and customer utilization equipmentto ensure s
17、afe handling of these products.5.2 Determination of the vapor pressure of liquefied petroleum gas is important for safety reasons to ensure that the maximumoperating design pressures of storage, handling, and fuel systems will not be exceeded under normal operating temperatureconditions.5.3 For liqu
18、efied petroleum gases, vapor pressure is an indirect measure of the most extreme low temperature conditions underwhich initial vaporization can be expected to occur. It can be considered a semi-quantitative measure of the amount of the mostvolatile material present in the product.6. Apparatus6.1 Vap
19、or Pressure Apparatus, constructed as illustrated in Fig. A1.1, and the various items of auxiliary equipment, arecompletely described in Annex A1.6.2 The vapor chamber of Test Method D323, maycan be interchangeable with the upper chamber of this method. Similarly,the liquid chamber (two-opening type
20、) of Test Method D323 is interchangeable with the B, 20 % lower chamber A1.1.4 of thismethod. Because of this interchangeability, the apparatus assembly of Test Method D323 mustshall pass, as a safety precaution,the hydrostatic test specified in A1.1.6 before using sameit in testing liquefied petrol
21、eum gas.6.3 Water Bath, temperature controlled, of a size suitable for the vapor pressure apparatus. See A1.3.6.4 Temperature Measuring Device, of verified accuracy and capable of monitoring the desired test temperature in the waterbath in the range of 35 to 70C to within 60.1C.7. Sampling and Sampl
22、e Handling7.1 Samples shall be obtained and stored in accordance with Practice D1265, or IP 181, Sampling Petroleum Gases, unless thetest samples can be taken directly from the source of the material to be tested.7.2 Any method of coupling the vapor pressure apparatus to the sample source canmay be
23、employed. Tubing, 6 to 7 mm (14in.) in diameter, of minimum length, of suitable-working pressure, and made of material corrosion-resistant to the products beingsampled, is satisfactory for this purpose. A flexible tubing connection of a satisfactory type greatly facilitates the purging andsampling o
24、perations. The tubing should be a conducting material or constructed with a built-in ground connection to minimize theeffect of static electricity.8. Preparation of Apparatus8.1 If the apparatus has been used for testing products other than the type of product to be tested, disassemble, clean thorou
25、ghly,and purge the parts in a stream of dry air.8.2 Assemble the apparatus with the inlet valve of the lower chamber open, the straight-through valve between the twochambers open, the bleeder valve closed, and with the proper range pressure gage attached.9. Procedure9.1 Safe means for the disposal o
26、f vapors and liquids during this operation and in the subsequent sampling operation mustshallbe provided.9.2 PurgingWith the assembled apparatus in an upright position, connect the inlet valve of the lower chamber to the samplesource with the sampling connection (7.2). Open the sample source valve t
27、o the apparatus. Cautiously open the bleeder valve onthe upper chamber, permitting the air or vapors, or both, in the apparatus to escape until the apparatus is full of liquid. Close thelower chamber inlet valve and open the bleeder valve to its wide open position. Allow the contained liquid to evap
28、orate until theapparatus is covered with white frost (may require more than one chilling), then invert the assembly, and expel any residualmaterial through the bleeder valve. Allow the residual vapors to escape until the pressure in the apparatus is essentiallyatmospheric, then close the bleeder val
29、ve.9.3 SamplingReturn the apparatus, now containing only vapors, to its normal upright position and open the inlet valve. Assoon as the apparatus attains essentially the same pressure as the pressure of the sample source, momentarily open the bleedervalve. If liquid does not promptly emerge, repeat
30、the purging step (9.2). If liquid appears immediately, close the bleeder and inletvalves in that order (Note 1). Close the valve on the sample source, and disconnect the sampling line. Immediately close theD1267 122straight-through valve between the two chambers and open the inlet valve, with the ap
31、paratus in an upright position. Close the inletvalve as soon as no more liquid escapes, and immediately open the straight-through valve.NOTE 1Transfer of the sample is facilitated by chilling the apparatus with a portion of the material under test.9.3.1 When using the 3313 % lower chamber (A1.1.3) p
32、roceed to 9.4.9.3.2 When using the 20 % lower chamber (Appendix A1.1.4), close the straight-through valve and again open the inlet topermit expulsion of the lower chamber contents. As soon as no more liquid escapes from the lower chamber, close the inlet valveand immediately open the straight-throug
33、h valve.9.3.3 The upper chamber, prior to this operation, is liquid full at some temperature that is normally below the environmentaltemperature. Since any warming of the apparatus would cause expansion of the liquid content of the upper chamber, leading topossible rupture of the chamber, it is nece
34、ssary that the procedural steps of providing free space in the apparatus be completedpromptly.9.4 Vapor Pressure Determination : Determination:9.4.1 Invert the apparatus and shake it vigorously. Return the apparatus to its normal upright position and immerse it in theconstant-temperature water bath
35、maintained at the test temperature (4.1). The apparatus including the bleeder valve coupling, butnot the pressure gage, must be immersed. Throughout the determination, the temperature of the water bath shall be checkedperiodically by means of the bath thermometer.temperature measuring device.9.4.1.1
36、 At test temperatures of 50C (122F) or below, from 37.8C (100F) up to and including 50C (122F), maintain thebath at 60.1C (0.2F). At test temperatures above 50C (122F), up to and including 70C (158F), maintain the bath at 60.3C(0.5F).9.4.1.2 Observe the apparatus assembly throughout the test period
37、to ensure freedom from leaks. Discontinue the test anddiscard the results at any time a leak is detected.9.4.2 After 5 min have elapsed, withdraw the apparatus from the water bath, invert it, shake it vigorously, and then return it tothe bath. Perform the shaking operation quickly to avoid excessive
38、 cooling of the apparatus and its contents. Thereafter, at intervalsof not less than 2 min, withdraw the apparatus from the bath, invert, shake it vigorously, and then return it to the bath. Prior toeach removal of the apparatus from the water bath, tap the gage lightly and observe the pressure read
39、ing. These operations willnormally require 20 to 30 min to ensure equilibrium. After this time, if consecutive observed gage readings are constant, recordthe pressure reading as the Uncorrected LP-Gas Vapor Pressure of the sample at the test temperature.9.4.3 If a pressure gage is used that is not c
40、alibrated against a dead-weight tester, it is necessary to determine if a gage correctionneeds to be applied to the pressure gage reading. Without removing the pressure gage from the apparatus or the apparatus fromthe bath, attach a test gage, previously calibrated against a dead-weight tester, to t
41、he bleeder valve outlet and open the bleedervalve. At the end of 5 min, compare the readings of the two gages. Record any correction thus determined as gage correction.9.4.3.1 Alternatively, if a pressure gage is used that has been calibrated against a dead-weight tester, then the gage correctionis
42、zero and it is not necessary to determine a gage correction as per 9.4.3, using a second test gage that has been calibrated againsta dead-weight tester.10. Calculation10.1 Correct the Uncorrected LP-Gas Vapor Pressure for gage errors (see 9.4.3 and 9.4.3.1).10.2 Convert the corrected vapor pressure
43、= (test gage reading) + (gage correction) as calculated in 9.4.3 to a standardbarometric pressure of 760 mm (29.92 in.) Hg by means of the following equation:10.2.1 LP-Gas Vapor Pressure: LP-Gas Vapor Pressure5corrected vapor pressure,kPa27602P1!0.1333 (1)5corrected vapor pressure,psi27602P1!0.0193
44、(2)where:P1 = observed barometric pressure, mm Hg.where:P1 = observed barometric pressure, mm Hg.10.2.2 LP-Gas Vapor Pressure: LP-Gas Vapor Pressure5corrected vapor pressure,kPa229.922P2!3.3864 (3)5corrected vapor pressure,psi229.922P2!0.4912 (4)where:P2 = observed barometric pressure, in. Hg.D1267
45、123where:P2 = observed barometric pressure, in. Hg.10.2.3 Conversion Factors: Conversion Factors:1kPa57.50064 mmHg50.295301 in. Hg (5)1psi551.7151 mmHg52.03603 in. Hg (6)11. Report11.1 Report the LP-Gas vapor pressure test results in terms of kilopascals to the nearest 5 kPa or pounds per square inc
46、h, gage,to the half unit, and the test temperature.nearest 0.5 psi gage, the test temperature, and reference this test method.12. Precision and Bias12.1 The following shall be used as a basis for judging the acceptability of results (95 % probability).12.1.1 RepeatabilityThe difference between two t
47、est results, obtained by the same operator with the same apparatus underconstant operating conditions on identical test materials would in the normal and correct operation of the test method, exceed thefollowing value only in one case in twenty:12 kPa 1.8 psi! (7)12.1.2 ReproducibilityThe difference
48、 between two single and independent results obtained by different operators working indifferent laboratories on identical test material would in the long run, in the normal and correct operation of the test method, exceedthe following value only in one case in twenty:19 kPa 2.8 psi! (8)12.2 BiasTheB
49、iasThe procedure in this test method for measuring vapor pressure has no bias because the value of vaporpressure is defined only in terms of this test method.13. Keywords13.1 natural gas liquids; liquifiedliquefied petroleum gases; vapor pressureANNEXES(Mandatory Information)A1. APPARATUS FOR VAPOR PRESSURE OF LIQUEFIED PETROLEUM (LP) GASESA1.1 Vapor Pressure Apparatus,consisting of two chambers, designated as the upper and lower chambers, shall conform to thefollowing requirements. To maintain the correct volume ratio between t
