1、Designation: D 1267 02 (Reapproved 2007)An American National StandardStandard Test Method forGage Vapor Pressure of Liquefied Petroleum (LP) Gases(LP-Gas Method)1This standard is issued under the fixed designation D 1267; the number immediately following the designation indicates the year oforiginal
2、 adoption or, in the case of revision, 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. Scope1.1 This test method covers the determination of the gagevapor pressur
3、es of liquefied petroleum gas products at tem-peratures of 37.8C (100F) up to and including a testtemperature of 70C (158F).1.2 The values stated in acceptable metric units are to beregarded as the standard. The values in parentheses are forinformation only.1.3 This standard does not purport to addr
4、ess all of thesafety concerns, if any, associated with its use. It is 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 hazardstatements, see 3.2.1 and Annex A2.2.
5、 Referenced Documents2.1 ASTM Standards:D 323 Test Method for Vapor Pressure of Petroleum Prod-ucts (Reid Method)D 1265 Practice for Sampling Liquefied Petroleum (LP)Gases, Manual MethodE1 Specification for ASTM Liquid-in-Glass Thermometers2.2 Institute of Petroleum Standard:IP 181 Sampling Petroleu
6、m Gases23. Terminology3.1 Definitions:3.1.1 vapor pressurethe pressure exerted by the vapor ofa liquid when in equilibrium with the liquid.3.2 Definitions of Terms Specific to This Standard:3.2.1 liquefied petroleum gasesnarrow boiling range hy-drocarbon mixtures consisting chiefly of propane or pro
7、pylene,or both, (WarningExtremely flammable. Harmful wheninhaled.) butanes and butylenes, or both, in which the contentof hydrocarbon compounds of higher boiling point than 0C(32F) is less than 5 % by liquid volume, and whose gagevapor pressure at 37.8C (100F) is not greater than approxi-mately 1550
8、 kPa (225 psi).4. Summary of Test Method4.1 The test apparatus, consisting of two interconnectedchambers and equipped with a suitable pressure gage, is purgedwith a portion of the sample which is then discarded. Theapparatus is then filled completely with the portion of thesample to be tested. Thirt
9、y-three and one-third to forty volumepercent of the sample content of the apparatus is immediatelywithdrawn to provide adequate free space for product expan-sion. The apparatus is then immersed in a water bath main-tained at the standard test temperature of 37.8C (100F) or,optionally, at some higher
10、 test temperature up to and includinga test temperature of 70C (158F).4.2 The observed gage pressure at equilibrium, after cor-recting for gage error and correcting to a standard barometricpressure, is reported as the LPG Vapor Pressure at the selectedtest temperature.5. Significance and Use5.1 Info
11、rmation on the vapor pressures of liquefied petro-leum gas products under temperature conditions from 37.8 to70C (100 to 158F) is pertinent to selection of properlydesigned storage vessels, shipping containers, and customerutilization equipment to ensure safe handling of these products.1This test me
12、thod is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.H0 on Liquefied Petroleum Gas.Current edition approved May 1, 2007. Published June 2007. Originallyapproved in 1953. Last previous edition approved in 2002 as
13、D 1267 02.2Available from Applied Science Publishers, Ripple Rd., Barking, Essex,England1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.2 Determination of the vapor pressure of liquefied petro-leum gas is important for safety reaso
14、ns to ensure that themaximum operating design pressures of storage, handling, andfuel systems will not be exceeded under normal operatingtemperature conditions.5.3 For liquefied petroleum gases, vapor pressure is anindirect measure of the most extreme low temperature condi-tions under which initial
15、vaporization can be expected to occur.It can be considered a semi-quantitative measure of the amountof the most volatile material present in the product.6. Apparatus6.1 Vapor Pressure Apparatus, constructed as illustrated inFig. A1.1, and the various items of auxiliary equipment, arecompletely descr
16、ibed in Annex A1.6.2 The vapor chamber of Test Method D 323, may beinterchangeable with the upper chamber of this method.Similarly, the liquid chamber (two-opening type) of TestMethod D 323 is interchangeable with the B, 20 % lowerchamber A1.1.4 of this method. Because of this interchange-ability, t
17、he apparatus assembly of Test Method D 323 mustpass, as a safety precaution, the hydrostatic test specified inA1.1.6 before using same in testing liquefied petroleum gas.7. Sampling and Sample Handling7.1 Samples shall be obtained and stored in accordance withPractice D 1265,orIP 181, Sampling Petro
18、leum Gases, unlessthe test samples can be taken directly from the source of thematerial to be tested.7.2 Any method of coupling the vapor pressure apparatus tothe sample source can be employed. Tubing, 6 to 7 mm (14 in.)in diameter, of minimum length, of suitable-working pressure,and made of materia
19、l corrosion-resistant to the products beingsampled, is satisfactory for this purpose. A flexible tubingconnection of a satisfactory type greatly facilitates the purgingand sampling operations. The tubing should be a conductingmaterial or constructed with a built-in ground connection tominimize the e
20、ffect of static electricity.8. Preparation of Apparatus8.1 If the apparatus has been used for testing products otherthan the type of product to be tested, disassemble, cleanthoroughly, and purge the parts in a stream of dry air.8.2 Assemble the apparatus with the inlet valve of the lowerchamber open
21、, the straight-through valve between the twochambers open, the bleeder valve closed, and with the properrange pressure gage attached.9. Procedure9.1 Safe means for the disposal of vapors and liquids duringthis operation and in the subsequent sampling operation mustbe provided.9.2 PurgingWith the ass
22、embled apparatus in an uprightposition, connect the inlet valve of the lower chamber to thesample source with the sampling connection (7.2). Open thesample source valve to the apparatus. Cautiously open thebleeder valve on the upper chamber, permitting the air orvapors, or both, in the apparatus to
23、escape until the apparatusis full of liquid. Close the lower chamber inlet valve and openthe bleeder valve to its wide open position.Allow the containedliquid to evaporate until the apparatus is covered with whitefrost (may require more than one chilling), then invert theassembly, and expel any resi
24、dual material through the bleedervalve. Allow the residual vapors to escape until the pressure inthe apparatus is essentially atmospheric, then close the bleedervalve.9.3 SamplingReturn the apparatus, now containing onlyvapors, to its normal upright position and open the inlet valve.As soon as the a
25、pparatus attains essentially the same pressureas the pressure of the sample source, momentarily open thebleeder valve. If liquid does not promptly emerge, repeat thepurging step (9.2). If liquid appears immediately, close thebleeder and inlet valves in that order (Note 1). Close the valveon the samp
26、le source, and disconnect the sampling line.Immediately close the straight-through valve between the twochambers and open the inlet valve, with the apparatus in anupright position. Close the inlet valve as soon as no more liquidescapes, and immediately open the straight-through valve.NOTE 1Transfer
27、of the sample is facilitated by chilling the apparatuswith a portion of the material under test.9.3.1 When using the 3313 % lower chamber (A1.1.3)proceed to 9.4.9.3.2 When using the 20 % lower chamber (AppendixA1.1.4), close the straight-through valve and again open theinlet to permit expulsion of t
28、he lower chamber contents. Assoon as no more liquid escapes from the lower chamber, closethe inlet valve and immediately open the straight-throughvalve.9.3.3 The upper chamber, prior to this operation, is liquidfull at some temperature that is normally below the environ-mental temperature. Since any
29、 warming of the apparatus wouldcause expansion of the liquid content of the upper chamber,leading to possible rupture of the chamber, it is necessary thatthe procedural steps of providing free space in the apparatus becompleted promptly.9.4 Vapor Pressure Determination:9.4.1 Invert the apparatus and
30、 shake it vigorously. Returnthe apparatus to its normal upright position and immerse it inthe constant-temperature water bath maintained at the testtemperature (4.1). The apparatus including the bleeder valvecoupling, but not the pressure gage, must be immersed.Throughout the determination, the temp
31、erature of the waterbath shall be checked periodically by means of the baththermometer.9.4.1.1 At test temperatures of 50C (122F) or below,maintain the bath at 60.1C (0.2F). At test temperaturesabove 50C (122F), up to and including 70C (158F),maintain the bath at 60.3C (0.5F).9.4.1.2 Observe the app
32、aratus assembly throughout the testperiod 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 apparatusfrom the water bath, invert it, shake it vigorously, and thenreturn it to the bath. Perform the sha
33、king operation quickly toavoid excessive cooling of the apparatus and its contents.Thereafter, at intervals of not less than 2 min, withdraw theapparatus from the bath, invert, shake it vigorously, and thenD 1267 02 (2007)2return it to the bath. Prior to each removal of the apparatusfrom the water b
34、ath, tap the gage lightly and observe thepressure reading. These operations will normally require 20 to30 min to ensure equilibrium. After this time, if consecutiveobserved gage readings are constant, record the pressurereading as the Uncorrected LP-Gas Vapor Pressure of thesample at the test temper
35、ature.9.4.3 If a pressure gage is used that is not calibrated againsta dead-weight tester, it is necessary to determine if a gagecorrection needs to be applied to the pressure gage reading.Without removing the pressure gage from the apparatus or theapparatus from the bath, attach a test gage, previo
36、usly cali-brated against a dead-weight tester, to the bleeder valve outletand open the bleeder valve. At the end of 5 min, compare thereadings of the two gages. Record any correction thus deter-mined as gage correction.9.4.3.1 Alternatively, if a pressure gage is used that has beencalibrated against
37、 a dead-weight tester, then the gage correctionis zero and it is not necessary to determine a gage correction asper 9.4.3, using a second test gage that has been calibratedagainst a dead-weight tester.10. Calculation10.1 Correct the Uncorrected LP-Gas Vapor Pressure forgage errors (see 9.4.3 and 9.4
38、.3.1).10.2 Convert the corrected vapor pressure = (test gagereading) + (gage correction) as calculated in 9.4.3 to a standardbarometric pressure of 760 mm (29.92 in.) Hg by means of thefollowing equation:10.2.1 LP-Gas Vapor Pressure5 corrected vapor pressure, kPa 760 P1! 0.1333 (1)5 corrected vapor
39、pressure, psi 760 P1! 0.0193 (2)where:P1= observed barometric pressure, mm Hg.10.2.2 LP-Gas Vapor Pressure5 corrected vapor pressure, kPa 29.92 P2! 3.3864 (3)5 corrected vapor pressure, psi 29.92 P2! 0.4912 (4)where:P2= observed barometric pressure, in. Hg.10.2.3 Conversion Factors:1 kPa 5 7.50064 m
40、mHg 5 0.295301 in. Hg (5)1 psi 5 51.7151 mmHg 5 2.03603 in. Hg (6)11. Report11.1 Report the LP-Gas vapor pressure test results in termsof kilopascals to the nearest 5 kPa or pounds per square inch,gage, to the half unit, and the test temperature.12. Precision and Bias12.1 The following shall be used
41、 as a basis for judging theacceptability of results (95 % probability).12.1.1 RepeatabilityThe difference between two test re-sults, obtained by the same operator with the same apparatusunder constant operating conditions on identical test materialswould in the normal and correct operation of the te
42、st method,exceed the following value only in one case in twenty:12 kPa 1.8 psi! (7)12.1.2 ReproducibilityThe difference between two singleand independent results obtained by different operators work-ing in different laboratories on identical test material would inthe long run, in the normal and corr
43、ect operation of the testmethod, exceed the following value only in one case in twenty:19 kPa 2.8 psi! (8)12.2 BiasThe procedure in this test method for measur-ing vapor pressure has no bias because the value of vaporpressure is defined only in terms of this test method.13. Keywords13.1 natural gas
44、liquids; liquified petroleum gases; vaporpressureANNEXES(Mandatory Information)A1. APPARATUS FOR VAPOR PRESSURE OF LIQUEFIED PETROLEUM (LP) GASESA1.1 Vapor Pressure Apparatus, consisting of two cham-bers, designated as the upper and lower chambers, shallconform to the following requirements. To main
45、tain the correctvolume ratio between the upper and lower chambers, the unitsshall not be interchanged without recalibrating to ascertain thatthe volume ratio is within satisfactory limits.A1.1.1 Upper ChamberThis chamber, as shown in Fig.A1.1 (c), shall be a cylindrical vessel 51 6 3mm(2618 in.)in d
46、iameter and 254 6 3mm(10618 in.) in length, insidedimensions, with the inner surfaces of the ends slightly slopedto provide complete drainage from either end when held in avertical position. On one end of the chamber, a suitablebleeder-valve coupling (Fig. A1.1 (e) shall be provided toreceive the bl
47、eeder-valve assembly and the pressure gage. Inthe other end of the chamber an opening approximately 13 mm(12 in.) in diameter shall be provided for coupling with thelower chamber. Care shall be taken that the connections to theend openings do not prevent the chamber from drainingcompletely.A1.1.2 Bl
48、eeder-Valve AssemblyThe bleeder-valve forpurging the apparatus (Fig. A1.1)(d) shall be a normal 6 mm(14 in.) valve fitted into the side of the bleeder-valve couplingD 1267 02 (2007)3(Fig. A1.1 (e). The lower end shall be threaded to fit into theend fitting of the upper chamber, and the upper end sha
49、ll bethreaded to receive the gage coupling (Fig. A1.1 (h).A1.1.3 Lower Chamber 3313 %(Fig. A1.1 (b)Thischamber shall be a cylindrical vessel of such a volume that theratio of the volume of the upper chamber to the volume of thelower chamber is between the limits of 1.97 to 2.03 (NoteA1.2).A1.1.4 Lower Chamber 20 % (Fig. A1.1 (b)This cham-ber shall be a cylindrical vessel of such a volume that the ratioof the volume of the upper chamber to the volume of the lowerchamber is between the limits of 3.95 to 4.05 (Note A
