1、Designation: D1837 11Standard Test Method forVolatility of Liquefied Petroleum (LP) Gases1This standard is issued under the fixed designation D1837; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numbe
2、r 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 is a measure of the relative purity ofthe various types of liquefied petroleum (LP) gases and helpsto ensure suitable vola
3、tility performance. The test results, whenproperly related to vapor pressure and density of the product,can be used to indicate the presence of butane and heaviercomponents in propane type LP-gas, and pentane and heaviercomponents in propane-butane and butane type fuels. Thepresence of hydrocarbon c
4、ompounds less volatile than those ofwhich the LP-gas is primarily composed is indicated by anincrease in the 95 % evaporated temperature.1.2 When the type and concentration of higher boilingcomponents is required, chromatographic analysis should beused.1.3 The values stated in SI units are to be reg
5、arded as thestandard. The values given in parentheses are for informationonly.1.4 WARNINGMercury has been designated by manyregulatory agencies as a hazardous material that can causecentral nervous system, kidney and liver damage. Mercury, orits vapor, may be hazardous to health and corrosive tomate
6、rials. Caution should be taken when handling mercury andmercury containing products. See the applicable product Ma-terial Safety Data Sheet (MSDS) for details and EPAswebsitehttp:/www.epa.gov/mercury/faq.htmfor addi-tional information. Users should be aware that selling mercuryand/or mercury contain
7、ing products into your state or countrymay be prohibited by law.1.5 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 appro-priate safety and health practices and determine the appli
8、ca-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D96 Test Method for Water and Sediment in Crude Oil byCentrifuge Method (Field Procedure)3D1796 Test Method for Water and Sediment in Fuel Oils bythe Centrifuge Method (Laboratory Procedure)E1 Specification f
9、or ASTM Liquid-in-Glass Thermometers3. Summary of Test Method3.1 Refrigerate the sample by means of a cooling coil andcollect 100 mL of liquid in a weathering tube. Allow toevaporate (“weather”) at ambient pressure under specifiedconditions that approximate a single plate distillation. Correctthe ob
10、served temperature, when 5 mL of liquid test portionremains, for barometric pressure and thermometer ice pointerror, and report as the 95 % evaporation temperature.4. Significance and Use4.1 Volatility, expressed in terms of the 95 % evaporatedtemperature of the product, is a measure of the amount o
11、f leastvolatile components present in the product. Coupled with avapor pressure limit, it serves to ensure essentially single-component products in the cases of commercial grades ofpropane and butane. When volatility is coupled with a vaporpressure limit which has been related to density, as in the
12、caseof the commercial PB-mixture, the combination serves toassure essentially two component mixtures for such fuels.When coupled with a proper vapor pressure limit, this mea-surement serves to assure that special-duty propane productswill be composed chiefly of propane and propylene and thatpropane
13、will be the major constituent.1This test method 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 Oct. 1, 2011. Published November 2011. Originallyapproved in
14、1961. Last previous edition approved in 2007 as D183702a(2007).DOI: 10.1520/D1837-11.2For 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 Document Summary
15、page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.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.
16、5. Apparatus5.1 Weathering TubeAcentrifuge tube, cone-shaped, con-forming to the dimensions given in Fig. 1 and made ofthoroughly annealed heat-resistant glass.4The shape of thelower tip of the tube is especially important. The taper shall beuniform and the bottom shall be rounded as shown in Fig. 1
17、.The tubes shall comply in wall thickness to ASTM centrifugetube requirements (Note 1). The graduation tolerances aregiven in Table 1.NOTE 1Requirements for centrifuge tubes appear in Test MethodsD96 and D1796.5.2 Tube SupportMeans shall be provided for supportingthe weathering tube by its neck in a
18、 vertical position.5.3 Water Bath (for use in tests on butane and propane-butane mixture types of liquefied petroleum gas only). Ashallow container filled with clean water having a maintainedtemperature ranging from 15 to 21C (60 to 70F) and a depthof 38 mm (112 in.).5.4 ThermometerASTM Armored Weat
19、hering Test Ther-mometer having a range from 50 to 5C (58 to 41F) andconforming to the requirements for Thermometer 99C92(99F86) as prescribed in Specification E1. Do not remove thearmor from the thermometer.5.5 Sampling Precooling Equipment:5.5.1 Cooling VesselAny suitable wide-mouthed metalcontain
20、er or Dewar flask at least 64 mm (212 in.) in insidediameter by 292 mm (1112 in.) deep.5.5.2 Cooling CoilApproximately 6 m (20 ft) of 4.8-mm(316-in.) outside diameter soft copper tubing, wound around ahollow mandrel at least 54 mm (218 in.) in outside diameter,with adjacent turns touching. Run the l
21、ower end of the tube upthrough the center of the mandrel before winding so that thefinished coil will fit snugly inside the cooling vessel. Whenassembled, the top of the coil shall be at least 25 mm (1 in.)below the top of the cooling vessel and the open ends of thecoil shall not be more than 100 mm
22、 (4 in.) above. Connect thedownstream end of the coil to a 3.2 mm (18 in.) needle valvehaving an outlet connection not more than 76 mm (3 in.) long(see Fig. 2).5.5.3 PrecoolantThis can be the liquefied petroleum gasfrom the same container from which a sample is to be taken.Other refrigerants having
23、a boiling point lower than the initialboiling point of the sample can be used. Use a nonflammableprecoolant if required.5.6 CharcoalFour grains of activated charcoal, approxi-mately 6 to 14 mesh in size, are required. The four grains shallbe similar in size (Note 2).NOTE 2Grains of charcoal are used
24、 as a boiling aid which reduces thetendency for the propane or butane to overflow the weathering tube as thepropane or butane evaporates.6. Procedure6.1 Positioning the ThermometerAdd water to the 5 mLline of the weathering tube. Add two grains of charcoal. Insert4Borosilicate glass has been found s
25、atisfactory for this purpose.NOTEFor graduation tolerances see Table 1.FIG. 1 Weathering TubeTABLE 1 Weathering Tube Graduation TolerancesRange, mLScaleDivision, mLLimit ofError, mL0.0 to 0.1 0.05 0.020.1 to 0.3 0.05 0.030.3 to 0.5 0.05 0.050.5 to 1.0 0.1 0.051.0to3.0 0.1 0.13.0to5.0 0.5 0.25.0 to 2
26、5.0 1.0 0.525.0 to 100.0 1.0 1.0D1837 112the armored thermometer as low as possible into the weather-ing tube. Observe and record the water level in the tube.Remove and discard the water and charcoal and clean and drythe weathering tube.6.2 Obtaining a Test Portion:6.2.1 Fill the cooling vessel with
27、 the precoolant so as tocover the cooling coil.6.2.2 The source of the sample (test portion) may be aprocess or delivery line, or a sample cylinder, taking care toobtain a liquid sample.6.2.3 Attach the inlet of the cooling coil to the source fromwhich the sample is to be taken with a short line con
28、nection of6.4 mm (14 in.) pipe (or larger), having a sampling valve largeenough to prevent vaporization of the material due to the dropin pressure across the valve seat.6.2.4 Purge the sampling line and cooling coil by openingboth the sampling valve and the 3.2 mm (18 in.) needle valveon the downstr
29、eam end of the cooling coil.6.2.5 Fill the weathering tube with the sample flowingthrough the cooling coil.6.2.6 Empty this first sample.6.2.7 Add two grains of similar-sized charcoal as was usedin 6.1, and then refill the weathering tube to the 100-mL markwith fresh liquid sample passing through th
30、e cooling coil.6.3 Placement of ThermometerCarefully insert the pre-cooled armored thermometer into the centrifuge tube, to thesame position as in 6.1, and center it in the tube by means ofa slotted cork. Take all 5 % residue readings at the levelestablished in 6.1.NOTE 3Inadequate precooling of the
31、 sample will result in excessivevaporization and loss of light components from the sample collected in theweathering tube. This results in proportionally more of the higher boilingcomponents in the sample in order to collect 100 mL of liquid.As a result,the test is made more severe, with a higher re
32、ported 95 % evaporationtemperature, which is on the conservative side.6.4 Weathering Butane and Propane-Butane Mixture Typesof Liquefied Petroleum Gas ProductsWhen the temperatureof the sample is below 12C (10F), allow it to weather in theatmosphere until the temperature has reached 12C (10F).Atthis
33、 point, place the weathering tube, with the armored ther-mometer still in place, in the water bath in a vertical position,submerging it to the 112-mL mark, and allow the contents toweather.6.5 Weathering Propane Type of Liquefied Petroleum GasProductsAllow the sample to weather in the atmosphere,tak
34、ing care to disturb the frost on the tube as little as possible.An acetone or alcohol swab can be used to remove frostsufficient to permit reading of the temperature.6.6 Reading of TemperatureWhen the liquid level in theweathering tube, with the armored thermometer still in place,corresponds to the
35、level previously determined in 6.1, read andrecord the temperature of the sample in accordance with 6.4and 6.5.6.7 Temperature CorrectionFollowing the final tempera-ture reading (6.6), remove the armored thermometer from theweathering tube and place it in a bath of finely crushed ice upto the immers
36、ion point. Observe the reading of the thermom-eter when a constant reading is obtained. If the thermometerreading is less than 0C (32F), add the fraction of a degree itis low to the final test reading. If the thermometer reading ismore than 0 (32F), subtract the fraction of a degree that it ishigh f
37、rom the final test reading. If the thermometer readingvaries more than 0.5C (1F), the test result is invalid. Repeatthe procedure using an accurate thermometer.NOTE 4A high reading of the thermometer when it is placed in iceusually indicates that there is a break in the mercury-thallium thread. This
38、can be corrected by warming the thermometer gently in a warm water bathto drive the break upward into the expansion chamber at the top of thethermometer. While the mercury-thallium is continuous in the upperchamber, tap the bottom of the thermometer on a hard, but cushionedsurface, to join the liqui
39、d into a continuous thread. A low reading in iceusually indicates that some of the liquid has remained in the expansionchamber. To correct this, allow the thermometer to warm so the liquidenters the chamber and tap as previously instructed.7. Interpretation of Results7.1 Correct the thermometer at t
40、he 95 % boiling point (5 %residue) for the thermometer error (6.7).7.2 Correct the observed temperature for the thermometererror from the observed atmospheric pressure in kPa (millime-tres of mercury) to a base barometric pressure of 101 kPa (760mm).7.3 In the weathering test for propane, add 0.3C (
41、0.6F) tothe corrected temperature for each 1.3 kPa (10 mm Hg) that thetest is conducted below 101 kPa (760 mm) pressure, or subtractNOTEThe coils in the drawing are extended for clarity.FIG. 2 Precooling EquipmentD1837 1130.3C (0.6F) from the observed temperature for each 1.3 kPa(10 mm Hg) that the
42、test is conducted above 101 kPa (760mm).7.4 In the weathering test for butane and propane-butanemixtures, add 0.4C (0.7F) to the corrected temperature foreach 1.3 kPa (10 mm Hg) that the test is conducted below 101kPa (760 mm) pressure, or subtract 0.4C (0.7F) from theobserved temperature for each 1
43、.3 kPa (10 mm Hg) that the testis conducted above 101 kPa (760 mm).8. Precision and Bias8.1 The following criteria should be used for judging theacceptability of results (95 % confidence):8.1.1 RepeatabilityThe difference between two test re-sults obtained by the same operator with the same apparatu
44、sunder constant operating conditions on identical test materialswould in the normal and correct operation of the test method,exceed the following value only in one case in twenty:0.6C (1.0F)8.1.2 ReproducibilityThe difference between two singleand independent results obtained by different operators
45、work-ing in different laboratories on identical test material would inthe long run, in the normal and correct operation of the testmethod, exceed the following value only in one case in twenty:1.0C (1.7F) for butane and propane-butane mixtures,and1.3C (2.3F) for propane8.2 BiasThe procedure in this
46、test method for measuringvolatility of LP-gases has no bias because the volatility isdefined only in terms of this test method.9. Keywords9.1 butane; liquefied petroleum (LP) gases; LPG; propane;volatilitySUMMARY OF CHANGESSubcommittee D02.H0 has identified the location of selected changes to this s
47、tandard since the last issue(D183702a(2007) that may impact the use of this standard.(1) Added new 1.4, mercury warning caveat.(2) Divided 6.2 into subsections.(3) Added new 6.2.2 to clarify the source of samples.ASTM International takes no position respecting the validity of any patent rights asser
48、ted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by
49、the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee
