1、Designation: D 2158 05Designation: 317/95An American National StandardStandard Test Method forResidues in Liquefied Petroleum (LP) Gases1This standard is issued under the fixed designation D 2158; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、 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. Scope*1.1 This test method covers the determination of extraneousmaterials weathering above 38C that
3、 are present in liquefiedpetroleum gases. The extraneous materials will generally bedissolved in the LPG, but may have phase-separated in someinstances.1.2 Liquefied petroleum gases that contain certain anti-icingadditives can give erroneous results by this test method.1.3 Although this test method
4、has been used to verifycleanliness and lack of heavy contaminants in propane formany years, it might not be sensitive enough to protect someequipment from operational problems or increased mainte-nance. A more sensitive test, able to detect lower levels ofdissolved contaminants, could be required fo
5、r some applica-tions.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 appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior t
6、o use.2. Referenced Documents2.1 ASTM Standards:2D96 Test Methods for Water and Sediment in Crude Oil byCentrifuge Method (Field Procedure)3D 1796 Test Method forWater and Sediment in Fuel Oils bythe Centrifuge Method (Laboratory Procedure)D 1835 Specification for Liquefied Petroleum (LP) GasesE1 Sp
7、ecification for ASTM Liquid-in-Glass Thermometers2.2 Other Document:IP Appendix A43. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 oil stain observation, nthe volume of solvent-residue mixture required to yield an oil stain or ring thatpersists for 2 minutes under specified con
8、ditions on absorbentpaper.3.1.2 residue, nthe volume, measured to the nearest 0.05mL, of the residual material boiling above 38C resulting fromthe evaporation of 100 mL of sample under the specifiedconditions of this test method.3.1.3 solvent-residue mixture, na mixture (solution) of 10mL of solvent
9、 with any residue remaining in the centrifugetube at the conclusion of the first step in this test method.4. Summary of Test Method4.1 A 100-mL sample of liquefied petroleum gas is weath-ered in a 100-mL centrifuge tube. The volume of residueremaining after heating the tube to 38C is measured andrec
10、orded.4.2 To dissolve any residue, 10 mLof solvent is added to thecentrifuge tube. Small, measured volumes of solvent-residuemixture are deposited on an absorbent paper in a specifiedmanner. The appearance of the absorbent paper to which theresidue solution has been added in measured increments isob
11、served and recorded.5. Significance and Use5.1 Control over the residue content (required by Specifica-tion D 1835) is of considerable importance in end-use appli-cations of LPG. In liquid feed systems residues can lead totroublesome deposits and, in vapor withdrawal systems, resi-dues that are carr
12、ied over can foul regulating equipment. Those1This 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 Nov. 1, 2005. Published November 2005. Origina
13、llyapproved in 1963. Last previous edition approved in 2004 as D 215804.2For 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 page onthe AS
14、TM website.3Withdrawn.4Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR,U.K. www.energyinstpubs.org.uk1*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 St
15、ates.that remain will accumulate, can be corrosive, and willcontaminate following product. Water, particularly if alkaline,can cause failure of regulating equipment and corrosion ofmetals.6. Interferences6.1 Solid contaminants such as rust, scale or dirt caninterfere with this test method, which is
16、not intended forrepresentative measurement of solid, undissolved contami-nants.7. Apparatus7.1 Centrifuge Tube, 100-mL graduated, conforming todimensions given in Fig. 1. The first 0.5 mL shall be graduatedin 0.05-mL increments. The shape of the lower tip of the tubeis especially important. The tape
17、r shall be uniform and thebottom shall be rounded as shown in Fig. 1. Tubes shall bemade of thoroughly annealed heat-resistant glass. Volumetricgraduation tolerances, based on air-free water at 20C, aregiven in Table 1. Detailed requirements for centrifuge tubesappear in Test Methods D96and D 1796.7
18、.2 Cooling Coil and Cooling Bath, a minimum length of 6m of 5 to 7-mm outside diameter copper tubing wound to adiameter of 63.5 6 1.5-mm outside diameter, and assembled ina suitable cooling bath. (See Fig. 2 as an example.)7.2.1 Mechanical refrigeration is permitted provided thatthe coolant temperat
19、ure is below 43C. If dry ice is used, anon-glass dewar or vessel is recommended.7.3 Syringe, 2-mL graduated in 0.1 mL and equipped with aneedle 200 6 5 mm long. The needle may be either a sharpFIG. 1 Cone-Shaped Centrifuge Tube, 203 mmD2158052needle (ordinary medical syringe needle) or a safe, non-s
20、harpsyringe needle to avoid a puncture hazard. Alternatively, anequivalent liquid dispensing device capable of delivering0.1-mL increments may be used, such as a 0.1-mL pipette.7.4 Temperature Measuring Device, that is intrinsicallysafe, with accuracy equal to or better than Specification E1orIP App
21、endix A shall be used. Thermometers conforming toSpecification E1or IP Appendix A have been found to besatisfactory.Low Range 38C to + 50C IP 1C/ASTM 5Cor IP 2C/ASTM 6CHigh Range 20C to + 50C ASTM 57CNOTE 1When a thermometer or a water bath, or both, are notavailable, for example when conducting a f
22、ield test, a satisfactoryalternative for screening purposes is to warm the tip of the centrifuge tubewith the hand.7.4.1 For routine testing, a general purpose thermometerwith 0.5C subdivisions and a maximum scale error of 0.5Cmay be used.7.5 Absorbent Paper, white, 125-mm diameter. Mediumgrade, rap
23、id filter paper has been found to be satisfactory. Inthis test method, the paper will be referred to as “filter paper.”7.6 Solvent Wash Bottle, typically polyethylene.7.7 Water Bath, controlled at 38 6 2C.7.8 Copper Wire, 1.6 6 0.1-mm diameter, 300 6 10-mmlong.7.9 Clamp, suitable for holding the cen
24、trifuge tube duringweathering.8. Reagents and Materials8.1 SolventHPLC-grade pentane or cyclopentane. An-other grade of solvent may be used provided that it meets therequirements of 10.2.8.1.1 Although pentane is the preferred solvent for use inthis test method, cyclopentane may be substituted for p
25、entanewhenever the ambient temperature or altitude is too high toenable the convenient handling of pentane.8.1.2 Storage of solvent in a polyethylene wash bottle forseveral days contaminates the solvent. Therefore, do not useany solvent that has remained in a polyethylene wash bottle formore than on
26、e day.9. Hazards9.1 Note that there is a significant fire hazard from LPGvapors, and since the boiling point of LPG can be as low as41C, there is a risk of freezing “burns.” Take appropriatesafety precautions to prevent ignition or fire, and wear suitableprotective equipment to protect against skin
27、contact with liquidor vaporizing LPG.9.2 Operators should wear a grounded antistatic wrist strap.The use of an antistatic floor mat and grounding the samplecylinder are also advised.10. Preparation of Apparatus10.1 Wash all glassware that is to be used in the test in theselected solvent.10.2 Verific
28、ation of cleanliness of glassware and solvent.10.2.1 Add 10 mL of a new sample of solvent to thecentrifuge tube.10.2.2 Mark the center of the filter paper with a pencil orother non-pentane-soluble writing tool.10.2.3 Fill the syringe or equivalent liquid dispensing de-vice (see 7.3) with a portion o
29、f the solvent drawn from thecentrifuge tube and direct 0.1-mL portions of the solvent to themark on the paper.10.2.3.1 The solvent is added in 0.1-mL increments toconfine the solvent ring to a circle about 30 to 35 mm indiameter. The filter paper should be held level during thesolvent addition. One
30、method is to place it on a 250-mLbeaker.10.2.4 Allow the solvent to evaporate for 2 min, and notethe persistence of an oil ring.10.2.4.1 The presence of an oil ring shall be observed byholding the dry filter paper between the eye and a brightincandescent light or strong daylight.TABLE 1 Centrifuge T
31、ube Graduation TolerancesRange, mLScale, Division,mLLimit of Error,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 25.0 1.0 0.525.0 to 100.0 1.0 1.0NOTECoils in the drawing are extended for clarity.FIG. 2 Precooling EquipmentD21
32、5805310.2.4.2 If no oil ring appears after 1.5 mL of solvent hasbeen added, the solvent and glassware are satisfactory.10.2.4.3 The appearance of an oil ring indicates eitherimproperly cleaned glassware or contaminated solvent.11. Procedure11.1 Residue Measurement:11.1.1 Attach the cooling coil to t
33、he LPG sample source,cool the coil to below the boiling point of the sample, and flushthe coil and sampling line.11.1.2 Rinse and cool the centrifuge tube with the materialto be sampled and then fill it to the 100-mL mark with arepresentative sample of LPG.11.1.3 Immediately insert the copper wire t
34、hrough a clean,slotted cork or a clean, loose-fitting plug of cotton or cleansingtissue in the mouth of the centrifuge tube. The wire helps toprevent superheating and resulting bumping (erratic or exces-sive boiling), and the cork (or plug) will keep out air ormoisture while the sample is weathering
35、.11.1.4 If more than 10 mL of the sample is lost because ofbumping, obtain a new sample and repeat the test.11.1.5 Allow the sample to weather, using artificial heatingif the ambient temperature or type of sample requires it. If,when weathering has ceased and the tube has reached ambienttemperature,
36、 a visible residue remains, place the tip of the tubein a water bath at 38C for 5 min.11.1.6 Record the volume of any remaining residue to thenearest 0.05 mL, and the presence of extraneous matter, ifobserved.11.1.7 Perform the oil stain observation described in 11.2even if there is no apparent or v
37、isible residue in the centrifugetube. Experience has shown that there can be a thin film of oilon the inner surface of the centrifuge tube that is difficult to seeand does not give a measurable volume, but can still give a ringor stain in the Oil Stain Observation procedure.11.2 Oil Stain Observatio
38、n:11.2.1 Add sufficient solvent to the centrifuge tube contain-ing the residue described in 11.1.5 to restore the volume to 10mL. Add the solvent from the wash bottle and carefully washdown the sides of the tube. Stir well so that any residue at thebottom of the tube is dissolved uniformly in the so
39、lvent.Stirring with the syringe needle (see 7.3) or pipette has beenfound satisfactory. This mixture will be referred to as thesolvent-residue mixture.11.2.2 Mark the center of a clean white filter paper.11.2.3 Fill the syringe or equivalent liquid dispensing de-vice (see 7.3), and direct 1.5 mL of
40、the solvent-residue mixtureat the center of the paper at an appropriate rate such that thewetted circle is maintained at about 30 to 35 mm in diameter.If desired, steps 11.2.3 and 11.2.4 may be omitted, and the testcontinued according to 11.2.5.11.2.4 After directing the entire 1.5 mL of residue sol
41、utiononto the filter paper and at the end of a 2-min waiting period,if no oil ring persists when holding the dry filter paper betweenthe eye and a bright incandescent light or strong daylight,discontinue the test and go to 12.1.11.2.5 If a stain or ring is discernible, determine the volumeof the sol
42、vent-residue mixture at which the oil stain or ring firstpersists for 2 min on a new filter paper by adding thesolvent-residue mixture in 0.1-mL increments, waiting 2 minafter each addition, and inspecting the paper for an oil stain atthe end of the 2-min period.11.2.6 Record the volume in millilitr
43、es of the solvent-residue mixture required to yield a persistent oil stain or ring asthe oil stain observation.11.2.7 Alternatively, if a product specification calls foradding a specified amount of solvent-residue mixture to thefilter paper, add the specified quantity in 0.1 mL increments,and report
44、 the result at the specified total amount.11.2.7.1 Specification D 1835 specifies that 0.3 mL ofsolvent-residue mixture shall be deposited on the filter paper in0.1-mL increments.11.2.7.2 If there is no oil stain after the addition of 0.3 mLand a 2-min waiting period, report the result as “Pass.”11.
45、2.7.3 If an oil stain is observed at 0.3 mL after a 2-minwaiting period, report the result as “Fail.”11.3 Any solvent transferred to the wash bottle for purposesof running the test shall either be used in testing during thesame day or discarded.11.4 It has been noted that at low ambient temperatures
46、(below about 5C) materials in the gasoline boiling range willleave an oil stain or ring that persists after 2 min. Oil staindeterminations should be made in a protected area where thetemperature is above 5C. If it is necessary to determine the oilstain at temperatures below 5C, allow 10 min for oil
47、stainpersistence.12. Report12.1 Report the results as:12.1.1 Residue on evaporation to the nearest 0.05 mL, and12.1.2 Oil stain observation to the nearest 0.1 mL.12.2 Alternatively, if the application of this test method callsfor passing or failing the oil stain requirement at a specifiedvolume of s
48、olvent-residue mixture, report the result at thespecified volume as “Pass” or “Fail” (see 11.2.7).13. Precision and Bias13.1 PrecisionPrecision has not been determined on thismethod in terms of residue and oil stain results. Precision hadbeen determined in terms of R and O numbers, as given inAppend
49、ix X1.13.2 BiasThe procedure in this test method for measuringresidues in LPGas has no bias, because the residues are definedonly in terms of this test method.14. Keywords14.1 contaminants; liquefied petroleum gases; LPG; oilstain; residueD2158054APPENDIX(Nonmandatory Information)X1. CALCULATION OF R AND O NUMBERSINTRODUCTIONHistorically, D 2158 has included indices for R and O which give the residue and oil stain resultsin whole numbers rather than the decimal results of this test method. These results have been referredto as “normalized results.” Since
