1、Designation: D873 12 British Standard 4456Designation: 138/99Standard Test Method forOxidation Stability of Aviation Fuels (Potential ResidueMethod)1This standard is issued under the fixed designation D873; the number immediately following the designation indicates the year oforiginal adoption or, i
2、n the case 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 T
3、his test method2covers the determination of thetendency of aviation reciprocating, turbine, and jet engine fuelsto form gum and deposits under accelerated aging conditions.(WarningThis test method is not intended for determiningthe stability of fuel components, particularly those with a highpercenta
4、ge of low boiling unsaturated compounds, as thesemay cause explosive conditions within the apparatus.)NOTE 1For the measurement of the oxidation stability (inductionperiod) of motor gasoline, refer to Test Method D525.1.2 The accepted SI unit of pressure is the kilo pascal (kPa);the accepted SI unit
5、 of temperature is C.1.3 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 tomaterials. Caution should be taken when handling mercury andm
6、ercury 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 containing products into your state or countrymay be prohibited
7、by law.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 to use.2. Refer
8、enced Documents2.1 ASTM Standards:3D381 Test Method for Gum Content in Fuels by Jet Evapo-rationD525 Test Method for Oxidation Stability of Gasoline (In-duction Period Method)D4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD5452 Test Method for Particulate Contamination in Avia-
9、tion Fuels by Laboratory FiltrationE1 Specification for ASTM Liquid-in-Glass Thermometers3. Terminology3.1 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.3.2 Definitions
10、of Terms Specific to This Standard:3.2.1 insoluble gum, ndeposit adhering to the glasssample container after removal of the aged fuel, precipitate,and soluble gum.3.2.1.1 DiscussionInsoluble gum is obtained by measur-ing the increase in mass of the glass sample container.3.2.2 potential gum, nsum of
11、 the soluble and insolublegum.3.2.3 precipitate, nsediment and suspended material in theaged fuel, obtained by filtering the aged fuel and washingsfrom the glass sample container.3.2.4 soluble gum, ndeterioration products present at theend of a specific aging period. These deterioration productsexis
12、t in solution in the aged fuel and as the toluene-acetonesoluble portion of the deposit on the glass sample container.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.14 on Stability and Cleanlin
13、ess of Liquid Fuels.This test method has been approved by the sponsoring committees and acceptedby the Cooperating Societies in accordance with established procedures.Current edition approved June 1, 2012. Published October 2012. Originallyapproved in 1946. Last previous edition approved in 2007 as
14、D87302(2007). DOI:10.1520/D0873-12.2Further information can be found in the June 1978, January 1979, and June1986 editions of the Institute of Petroleum Review.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of
15、 ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.4.1 DiscussionThe soluble gum is obtained as a non-volatile residue by evaporating
16、the aged fuel and the toluene-acetone washings from the glass sample container.3.2.5 total potential residue, nsum of the potential gumand the precipitate.4. Summary of Test Method4.1 The fuel is oxidized under prescribed conditions in apressure vessel filled with oxygen. The amounts of solublegum,
17、insoluble gum, and precipitate formed are weighed.(WarningIn addition to other precautions, to provide pro-tection against the possibility of explosive rupture of thepressure vessel, the pressure vessel should be operated behindan appropriate safety shield.)5. Significance and Use5.1 The results (of
18、 these tests) can be used to indicatestorage stability of these fuels. The tendency of fuels to formgum and 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
19、 Pressure Vessel, Burst Disc Assembly, GlassSample Container and Cover, Accessories and Pressure Gage,as described in the Annex to Test Method D525.(WarningProvision shall be made to safely vent any expelled gases orflames away from the operator, other personnel, or flammablematerials as a safety pr
20、ecaution if the burst-disc ruptures.)NOTE 2Pressure vessels conforming to Test Method D525-80 are alsosuitable, 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
21、 below andconforming to the requirements as prescribed in SpecificationE1, or specifications for IP 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 resista
22、ncethermometers, that can provide equivalent or better accuracy andprecision, may be used in place 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
23、, as described in the Annex to TestMethod D525. The liquid shall be water or a mixture ofethylene 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 th
24、an water is used, an appropriatemechanical stirrer/mixer shall be used to maintain uniformityof 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 withou
25、t this device are strongly urged to have theequipment retrofitted to ensure safe operation.NOTE 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 m
26、ay beused in place of the liquid bath as long as the sample heating rate andsample temperature are 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 re
27、commended.7. Reagents and Materials7.1 Gum SolventA mixture of equal volumes of tolueneand acetone.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 D4057.9. Prepar
28、ation of Apparatus9.1 Thoroughly clean a glass sample container to removetraces of any adhering 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 labora
29、tory. The criterion forsatisfactory cleaning shall be a matching of the quality of thatobtained 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
30、, rinsing with distilledwater and drying). For this comparison, visual appearance andmass loss 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
31、; this procedure remains thereference cleaning practice and, as such, may function as analternate 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
32、 with tap water and then withdeionized or distilled water, and dry in an oven at 100 to 150Cfor 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 i
33、nsoluble gumis negligible in aviation reciprocating engine fuels. Therefore,the glass sample container 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
34、 of the containerrecorded.9.2 Drain any fuel from the pressure vessel and wipe theinside of the 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 fro
35、m the stem, rod, and needlevalve with gum solvent. The pressure vessel, the valve, and allD873 122connecting lines shall be thoroughly dry before each test isstarted. (WarningVolatile peroxides, which may haveformed during a previous test, may accumulate in theequipment, producing a potentially expl
36、osive environment.Special care in cleaning after each test is needed to ensure thatthe filler rod, stem, and needle valve are free of theseperoxides.)9.3 If a thermostatically controlled constant temperatureoxidation bath is used, adjust the temperature to 100 6 0.1Cand maintain it within this tempe
37、rature range for the durationof the test.9.4 If a boiling water oxidation bath is used, adjust thetemperature within the range from 99.5 to 100.5C by theaddition of water or a higher boiling liquid such as ethyleneglycol. Factors are given in Table 1 to adjust the “X” hour agingtime if the bath temp
38、erature at the start of the test deviates from100C.10. Procedure10.1 Bring the pressure vessel 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 int
39、othe weighed glass sample container first, before placing theglass sample container into the 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
40、to escapeslowly through the needle valve at a rate not to exceed 345kPa/min. Repeat the charging 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
41、 rapid dropin pressure (generally not over 40 kPa), which can be observedbecause of the solution 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
42、 oxidation baths, being careful to avoid shaking, andrecord the time of immersion as the starting 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 fac
43、torsgiven in Table 1.10.3 At the completion of the period of oxidation, removethe pressure vessel 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 re
44、moval from the bath, usingwater 35C. Release the pressure slowly through the needlevalve at 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, stopp
45、eredcylinder, that will allow mixing of approximately 120 mL, if novisible precipitate is observed 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 rin
46、ses thoroughly,and preserve the mixture for the determination of soluble gum.Proceed with the 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 oxidiz
47、ed fuel through the crucibleand save the filtrate. A vacuum filtration set-up has been foundsuitable to use, although precautions should be taken to avoidthe potential of static discharges, such as described in TestMethod D5452. Wash the interior of the glass container twicewith 10-mL portions of gu
48、m solvent to remove any gum orprecipitate. Filter the washings through the crucible, addingthem 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 ve
49、ssel to approximately roomtemperature (for at least 2 h), and weigh the crucible (that is,the 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 hours 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
