1、Designation: D 873 02Designation: 138/99An American National StandardBritish Standard 4456Standard Test Method forOxidation Stability of Aviation Fuels (Potential ResidueMethod)1This standard is issued under the fixed designation D 873; the number immediately following the designation indicates the
2、year oforiginal 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.This test method has been approved by the sponsoring committees
3、 and accepted by the Cooperating Societies in accordance withestablished procedures.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method2covers the determination of thetendency of aviation reciprocating, turbine, and jet engine fuelsto form gu
4、m and deposits under accelerated aging conditions.(WarningThis test method is not intended for determiningthe stability of fuel components, particularly those with a highpercentage of low boiling unsaturated compounds, as thesemay cause explosive conditions within the apparatus.)NOTE 1For the measur
5、ement of the oxidation stability (inductionperiod) of motor gasoline, refer to Test Method D 525.1.2 The accepted SI unit of pressure is the kilo pascal (kPa);the accepted SI unit of temperature is C.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its
6、 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.2. Referenced Documents2.1 ASTM Standards:D 381 Test Method for Existent Gum in Fuels by JetEvaporation3D 525 Test
7、Method for Oxidation Stability of Gasoline(Induction Period Method)3D 4057 Practice for Manual Sampling of Petroleum andPetroleum Products4D 5452 Test Method for Particulate Contamination in Avia-tion Fuels by Laboratory Filtration5E 1 Specification for ASTM Thermometers63. Terminology3.1 Definition
8、s of Terms Specific to This Standard3.1.1 The following definitions of terms are all expressed interms of milligrams per 100 mL of sample, after “X” hoursaging, “X” being the accelerated aging (oxidation) period at100C.3.1.1.1 insoluble gumdeposit adhering to the glass samplecontainer after removal
9、of the aged fuel, precipitate, andsoluble gum. Insoluble gum is obtained by measuring theincrease in mass of the glass sample container.3.1.1.2 potential gumsum of the soluble and insolublegum.3.1.1.3 precipitatesediment and suspended material in theaged fuel, obtained by filtering the aged fuel and
10、 washingsfrom the glass sample container.3.1.1.4 soluble gumdeterioration products present at theend of a specific aging period. These deterioration productsexist in solution in the aged fuel and as the toluene-acetonesoluble portion of the deposit on the glass sample container.The soluble gum is ob
11、tained as a nonvolatile residue byevaporating the aged fuel and the toluene-acetone washingsfrom the glass sample container.3.1.1.5 total potential residuesum of the potential gumand the precipitate.4. Summary of Test Method4.1 The fuel is oxidized under prescribed conditions in apressure vessel fil
12、led with oxygen. The amounts of solublegum, insoluble gum, and precipitate formed are weighed.(WarningIn addition to other precautions, to provide pro-tection against the possibility of explosive rupture of the1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and
13、 Lubricants and is the direct responsibility of SubcommitteeD02.14 on Stability and Cleanliness of Liquid Fuels.Current edition approved Dec. 10, 2002. Published March 2003. Originallyapproved in 1946. Last previous edition approved in 1999 as D 87399a.2Further information can be found in the June 1
14、978, January 1979, and June1986 editions of the Institute of Petroleum Review.3Annual Book of ASTM Standards, Vol 05.01.4Annual Book of ASTM Standards, Vol 05.02.5Annual Book of ASTM Standards, Vol 05.03.6Annual Book of ASTM Standards, Vol 14.03.1Copyright ASTM International, 100 Barr Harbor Drive,
15、PO Box C700, West Conshohocken, PA 19428-2959, United States.pressure vessel, the pressure vessel should be operated behindan appropriate safety shield.)5. Significance and Use5.1 The results (of these tests) can be used to indicatestorage stability of these fuels. The tendency of fuels to formgum a
16、nd deposits in these tests has not been correlated withfield performance (and can vary markedly) with the formationof gum and deposits under different storage conditions.6. Apparatus6.1 Oxidation Pressure Vessel, Burst Disc Assembly, GlassSample Container and Cover, Accessories and Pressure Gage,as
17、described in the Annex to Test Method D 525. (WarningProvision shall be made to safely vent any expelled gases orflames away from the operator, other personnel, or flammablematerials as a safety precaution if the burst-disc ruptures.)NOTE 2Pressure vessels conforming to Test Method D 525/1980 areals
18、o suitable, but the specified burst-disc shall be attached. The burst discassembly shall be mechanically designed to ensure that it cannot beincorrectly fitted.6.2 Thermometer, having a range as shown below andconforming to the requirements as prescribed in SpecificationE 1, or specifications for IP
19、 thermometers:Thermometer Range Thermometer NumberASTM IP95 to 103C 22C 24CNOTE 3Other temperature sensing devices that cover the temperaturerange of interest, such as thermocouples or platinum resistance thermom-eters, that can provide equivalent or better accuracy and precision, may beused in plac
20、e of the thermometers specified in 6.2.6.3 Drying Oven, air oven maintained at 100 to 150C.6.4 Forceps, corrosion-resistant, steel.6.5 Filtering Crucible, sintered-glass, fine porosity.6.6 Oxidation Bath, as described in the Annex to TestMethod D 525. The liquid shall be water or a mixture ofethylen
21、e glycol and water, as required. The temperature can becontrolled thermostatically at 100 6 0.2C, or by maintainingit at its boiling point, which must be between 99.5 to 100.5C.If a liquid medium other than water is used, an appropriatemechanical stirrer/mixer shall be used to maintain uniformityof
22、the liquid bath at 100 6 0.2C. A non self-resettable deviceshall be fitted on all new baths to ensure that the heater isswitched off if the liquid bath falls below a safe level. Users ofolder baths without this device are strongly urged to have theequipment retrofitted to ensure safe operation.NOTE
23、4Electric heating blocks are known to be used. These blockscan have heating capacities, heating rates, and heat transfer characteristicsthat differ from those of a liquid bath. An electric heating block may beused in place of the liquid bath as long as the sample heating rate andsample temperature a
24、re demonstrated to be equivalent to that of the liquidbath.6.7 Cooling VesselA desiccator or other type of tightlycovered vessel for cooling the beakers before weighing. Theuse of a drying agent is not recommended.7. Reagents and Materials7.1 Gum SolventA mixture of equal volumes of tolueneand aceto
25、ne.7.2 Oxygen, commercially available extra dry oxygen of notless than 99.6 % purity.8. Sampling8.1 Sample in accordance with the procedure for oxidationstability, as described in Practice D 4057.9. Preparation of Apparatus9.1 Thoroughly clean a glass sample container to removetraces of any adhering
26、 material. Immerse the container and itscover in a mildly alkaline or neutral pH laboratory detergentcleaning solution. The type of detergent and conditions for itsuse need to be established in each laboratory. The criterion forsatisfactory cleaning shall be a matching of the quality of thatobtained
27、 with chromic acid cleaning solutions (or some otherequivalently strong oxidizing non-chromium containing acidcleaning solutions) on used sample containers and covers(fresh chromic acid, 6-h soaking period, rinsing with distilledwater and drying). For this comparison, visual appearance andmass loss
28、on heating the glassware under test conditions maybe used. Detergent cleaning avoids the potential hazards andinconveniences related to the handling of highly corrosive andstrongly oxidizing acid solutions; this procedure remains thereference cleaning practice and, as such, may function as analterna
29、te to the preferred procedure, cleaning with detergentsolutions. Remove from the cleaning solution by means ofcorrosion-resistant steel forceps and handle only with forcepsthereafter. Wash thoroughly first with tap water and then withdeionized or distilled water, and dry in an oven at 100 to 150Cfor
30、 1 h. Cool the sample containers and covers for at least 2 hin the cooling vessel in the vicinity of the balance. Weigh to thenearest 0.1 mg, and record mass.9.1.1 Experience indicates that the amount of insoluble gumis negligible in aviation reciprocating engine fuels. Therefore,the glass sample co
31、ntainer need not be weighed when testingsuch fuels unless visible evidence of insoluble matter remainsin the container after treatment with gum solvent. In suchcases, the test must be repeated and the mass of the containerrecorded.9.2 Drain any fuel from the pressure vessel and wipe theinside of the
32、 pressure vessel and pressure vessel closure, firstwith a clean cloth moistened with gum solvent and then with aclean, dry cloth. Remove the filler rod from the stem, andcarefully clean any gum or fuel from the stem, rod, and needlevalve with gum solvent. The pressure vessel, the valve, and allconne
33、cting lines shall be thoroughly dry before each test isstarted. (WarningVolatile peroxides, which may haveformed during a previous test, may accumulate in the equip-ment, producing a potentially explosive environment. Specialcare in cleaning after each test is needed to ensure that the fillerrod, st
34、em, and needle valve are free of these peroxides.)9.3 If a thermostatically controlled constant temperatureoxidation bath is used, adjust the temperature to 100 6 0.1Cand maintain it within this temperature range for the durationof the test.9.4 If a boiling water oxidation bath is used, adjust thete
35、mperature within the range from 99.5 to 100.5C by theaddition of water or a higher boiling liquid such as ethyleneD873022glycol. Factors are given in Table 1 to adjust the “X” hour agingtime if the bath temperature at the start of the test deviates from100C.10. Procedure10.1 Bring the pressure vesse
36、l and the fuel to be tested to atemperature from 15 to 25C. Place the weighed glass samplecontainer in the pressure vessel and add 100 6 1 mL of testspecimen. Alternatively, transfer 100 6 1 mL of sample intothe weighed glass sample container first, before placing theglass sample container into the
37、pressure vessel. Cover the samecontainer, close the pressure vessel, and using a quick releasecoupling, introduce oxygen until a pressure from 690 to 705kPa is attained. Allow the gas in the pressure vessel to escapeslowly through the needle valve at a rate not to exceed 345kPa/min. Repeat the charg
38、ing and exhausting of the oxygenonce more in order to flush out the air originally present.Introduce oxygen again until a pressure of from 690 to 705 kPais attained and observe for leaks, ignoring an initial rapid dropin pressure (generally not over 40 kPa), which can be observedbecause of the solut
39、ion of oxygen in the sample. Assume theabsence of leaks, and proceed with the test if the rate ofpressure drop does not exceed 15 kPa in 10 min.10.2 Place the charged pressure vessel in one of the de-scribed oxidation baths, being careful to avoid shaking, andrecord the time of immersion as the star
40、ting time. Leave thepressure vessel in the oxidation bath for the specified “X” houraging time. If the temperature at the start of a test varies from100C, adjust the “X” hour aging time by the correction factorsgiven in Table 1.10.3 At the completion of the period of oxidation, removethe pressure ve
41、ssel from the bath. To minimize further oxida-tion of the test specimen and to provide for safe venting of thepressure vessel, cool the pressure vessel to approximately roomtemperature within 30 min after removal from the bath, usingwater #35C. Release the pressure slowly through the needlevalve at
42、a rate not to exceed 345 kPa/min. Take the pressurevessel apart, and remove the sample container.10.4 Transfer the oxidized fuel from the glass samplecontainer to a graduated flask, such as a graduated, stopperedcylinder, that will allow mixing of approximately 120 mL, if novisible precipitate is ob
43、served or if the amount is not specifi-cally required by specifications. Wash the interior of the glasssample container twice with 10-mL portions of gum solvent toremove any gum. Mix the oxidized fuel and rinses thoroughly,and preserve the mixture for the determination of soluble gum.Proceed with th
44、e test as specified in 10.6. If a precipitate isobserved, and if the amount is required by specifications,determine the initial mass of the filtering crucible (see 6.5) thatis to be used and filter the oxidized fuel through the crucibleand save the filtrate. A vacuum filtration set-up has been found
45、suitable to use, although precautions should be taken to avoidthe potential of static discharges, such as described in TestMethod D 5452. Wash the interior of the glass container twicewith 10-mL portions of gum solvent to remove any gum orprecipitate. Filter the washings through the crucible, adding
46、them to the oxidized fuel filtrate, and mix thoroughly. Preservethe mixture for the determination of soluble gum.10.5 Dry the crucible in an oven maintained at 100 to 150Cfor at least 1 h, cool in a cooling vessel to approximately roomtemperature (for at least 2 h), and weigh the crucible (that is,t
47、he crucible plus residue) to determine its final mass. Subtractthe initial mass of the crucible from the final mass of thecrucible. Record any increase in mass as precipitate, A.10.6 Dry the glass sample container in an oven maintainedat 100 to 150C for 1 h, cool in a cooling vessel, and weigh.Two h
48、ours has been found to be a suitable time to cool the glasssample container. Record any increase in mass as insolublegum, B.10.7 Divide the mixture obtained in 10.4 into two equalportions (within 2 mL), and determine the soluble gum existingtherein by the procedure and test conditions described in T
49、estMethod D 381, using in each test the entire half portion insteadof the 50-mL test specimen specified in Test Method D 381.Record the sum of the increase in mass of the two beakers assoluble gum, C, as calculated in accordance with the followingequation:C 5 1000 3 D2E! 1 F2G! 1 2X2Y! (1)where:C = soluble gum, mg/100 mL,D = mass of test specimen beaker 1 + residue, g,E = mass of test specimen beaker 1, g,F = mass of test specimen beaker 2 + residue, g,G = mass of test specimen beaker 2, g,X = mass of tare beaker (before), g, andY = mass of tare beaker
