1、Designation: G72/G72M 09Standard Test Method forAutogenous Ignition Temperature of Liquids and Solids in aHigh-Pressure Oxygen-Enriched Environment1This standard is issued under the fixed designation G72/G72M; the number immediately following the designation indicates the yearof original adoption or
2、, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the tem-perature at which liquids
3、and solids will spontaneously ignite.These materials must ignite without application of spark orflame in a high-pressure oxygen-enriched environment.1.2 This test method is intended for use at pressures of 2.1to 20.7 MPa (300 to 3000 psi). The pressure used in thedescription of the method is 10.3 MP
4、a (1500 psi). The testmethod, as described, is for liquids or solids with ignitiontemperature in the range from 60 to 425C (140 to 800F).1.3 This test method is for high-pressure pure oxygen. Thetest method may be used in atmospheres from 0.5 % to 100 %oxygen.1.4 An apparatus suitable for these requ
5、irements is de-scribed. This test method could be applied to higher pressuresand materials of higher ignition temperature. If more severerequirements or other oxidizers than those described aredesired, care must be taken in selecting an alternative safeapparatus capable of withstanding the condition
6、s.1.5 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewit
7、h the standard.1.6 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.
8、2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodG93 Practice for Cleaning Methods and Cleanliness L
9、evelsfor Material and Equipment Used in Oxygen-EnrichedEnvironments2.2 Federal Specification:3BB-O-925 Oxygen, Technical, Gas and Liquid2.3 Other Documents:MNL 36 Safe Use of Oxygen and Oxygen Systems: Guide-lines for Oxygen System Design, Materilas, Selection,Operations, Storage, and Transportation
10、4Compressed Gas Association Booklets G-1 and G-4.133. Summary of Test Method3.1 This autogenous ignition temperature test method isdesigned to expose solid or liquid sample material to increasingtemperature in a high-pressure reaction vessel. The reactionvessel (bomb), including a sample holding ass
11、embly, is pres-surized with the oxygen-enriched environment. The bomb isheated in an electric furnace at a predetermined rate. Thetemperature of the sample-holding assembly is monitored as afunction of time by means of a thermocouple and recordingpotentiometer.3.2 The minimum temperature required to
12、 cause the sampleto ignite spontaneously is determined at any selected systempressure. The point at which spontaneous ignition occurs isdenoted by a sudden rise in temperature and the destruction ofthe sample. The amount of rise in temperature is related to thesample size. A sample size is selected
13、to prevent damage to theequipment caused by exceeding safe system pressure ortemperature limits because of the temperature rise.3.3 The system is pressurized to the desired test pressure atthe start of the test. During the test as the temperature isincreased, the pressure increases. No effort is mad
14、e to controlthe pressure during the test. It is monitored only so that thepressure does not exceed a safe limit for the test equipment.1This test method is under the jurisdiction of ASTM Committee G04 onCompatibility and Sensitivity of Materials in Oxygen Enriched Atmospheres and isthe direct respon
15、sibility of Subcommittee G04.01 on Test Methods.Current edition approved Oct. 1, 2009 Published February 2010. Originallyapproved in 1982. . Last previous edition approved in 2001 as G7201. DOI:10.1520/G0072-09.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Cust
16、omer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Compressed Gas Association (CGA), 4221 Walney Rd., 5thFloor, Chantilly, VA 20151-2923, http:/.4ASTM Manual Series, Available from ASTM
17、, 100 Barr Harbor Drive, W.Conshohocken, PA 19428.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Significance and Use4.1 Most organic liquids and solids will ignite in a pressur-ized oxidizing gas atmosphere if heated to a suffic
18、iently hightemperature and pressure. This procedure provides a numericalvalue for the temperature at the onset of ignition undercarefully controlled conditions. Means for extrapolation fromthis idealized situation to the description, appraisal, or regula-tion of fire and explosion hazards in specifi
19、c field situations,are not established. Ranking of the ignition temperatures ofseveral materials in the standard apparatus is generally inconformity with field experience.4.2 The temperature at which material will ignite spontane-ously (AIT) will vary greatly with the geometry of the testsystem and
20、the rate of heating. To achieve good interlaboratoryagreement of ignition temperatures, it is necessary to useequipment of approximately the dimensions described in thetest method. It is also necessary to follow the describedprocedure as closely as possible.4.3 The decomposition and oxidation of som
21、e fully fluori-nated materials releases so little energy that there is noclear-cut indication of ignition. Nor will there be a clearindication of ignition if a sample volatilizes, distilling toanother part of the reaction vessel, before reaching ignitiontemperature.5. Apparatus5.1 Suitable component
22、s shall be assembled so that thespecified reaction vessel (bomb), including sample-holdingassembly, can be charged with oxygen and heated. Theassembly shall provide a means of recording time and tem-perature at which ignition occurs. A suitable assembly isillustrated in Fig. 1.5.2 Cylinder Oxygen, c
23、onforming to Federal SpecificationBB-O-925, Type I or oxygen of 99.5 % minimum purity.Oxygen of higher purity may be used if desired.5.3 Line Filter, sintered stainless steel, 5-m porosity,maximum pressure 206.8 MPa (30 000 psi), for 6.35-mm(14-in.) high-pressure tubing with a 3.18-mm (18-in.) port.
24、55.4 Compressor Pumps, diaphragm-type, air-driven.65.5 Valves, 6.35 mm (14 in.), 206.8 MPa (30 000 psi)working pressure, nonrotating stem valves.75.6 Pressure Gage, 20.7 MPa (3000 psi), 216 mm (812 in.).8Heise 2 or equivalent has been found satisfactory.5.7 Connecting Tubing, Type 316 stainless stee
25、l, 6.35 mm(14 in.), 448.1 MPa (65 000 psi) pressure rating at 37.8C(100F).95.8 High-Pressure Tees, Type 316 stainless steel with glandnuts and sleeves of Type 416 stainless steel, 6.35 mm (14 in.)high-pressure. Superpressure, Inc., Catalog No. 45-14311.10All connection fittings shall be of cold-draw
26、n Type 316stainless steel, 413.7 MPa (60 000 psi) maximum pressure,5Catalog No. 49-14405 available from Superpressure, Inc., Silver Spring, Md.20910 or equivalent has been found satisfactory.6Catalog No. 46-14035 available from Superpressure, Inc., Silver Spring, Md.20910 or equivalent has been foun
27、d satisfactory.7Catalog No. 44-13121 available from Superpressure, Inc., Silver Spring, Md.20910 or equivalent has been found satisfactory.8Model C available from Heise Bourdon Tube Co., Newton, Conn. 06740 orequivalent has been found satisfactory.9Catalog No. 45-11021 available from Superpressure,
28、Inc., Silver Spring, Md.20910 or equivalent has been found satisfactory.10Catalog No. 45-14311 available from Superpressure, Inc., Silver Spring, Md.20910 or equivalent has been found satisfactory.FIG. 1 AIT Equipment AssemblyG72/G72M 092tubing size 6.35 mm (14 in.) high-pressure and 14.3-mm(916-in.
29、) insertion depth.115.9 Pressure-Relief Blowout with Rupture Discs, pressure-relief blow-out assembly, Type 316 stainless steel, 6.35 mm (14in.), angle type12with 48.3 MPa (7000 psi) at 22.2C (72F)rupture disks.135.10 Reaction Vessel (Bomb)Asuitable reaction vessel forthe test method is cylindrical,
30、 approximately 65 mm (2916 in.)in outside diameter and 298 mm (1134 in.) long and weighs9.75 kg (2112 lb). The vessel is bored from a solid forging ofAISI 316SS (814 in.) depth, with a volume equal to approxi-mately 110 mL. The maximum working pressure at 427C(800F) is 82.7 MPa (12 000 psi).145.11 T
31、hermocouple AssemblyA Chromel-Alumel thermo-couple with suitable high-pressure fittings for the reactionvessel with a 203-mm (8-in.) thermocouple to extend into thereaction chamber.155.12 Heating JacketA 230-V, 1000-W single-phase heat-ing jacket designed to fit the reaction vessel should be used.16
32、5.13 Recorder, 0 to 1000C (0 to 2000F)A strip chartrecording pyrometer in the temperature range for the testmethod should be used.17The scale must be such that a suddenchange of 20C (36F) or more in temperature in the reactionvessel is clearly indicated.5.14 Inner Reaction VesselA borosilicate glass
33、 test tube15 by 125 mm.185.15 Sample HolderA borosilicate glass culture tube 10by 75 mm.195.16 Wire Support, fashioned from ChromelA, No. 21AWGwire.9Several turns of wire are wound on a mandrel ofsufficient size so that the resulting spring-like structure fits theinner reaction vessel snugly. A loop
34、 of wire is bent to hold thevessel at the proper height, positioning the thermocoupleassembly in the mouth of the sample holder (Fig. 2).5.17 Support Bushing, fitting into the reaction vessel coverand supporting the entire sample-holding assembly.205.18 Inner Reaction Vessel Stopper, fashioned from1
35、2.5-mm borosilicate glass tubing to fit in the inner reactionvessel. It must also conform to the dimensions in Fig. 3.6. Materials6.1 Nitric AcidConsisting of 5% by volume of AnalyticalReagent grade nitric acid and deionized water.6.2 Alkaline CleanerConsisting of a solution of 15 g ofsodium hydroxi
36、de (NaOH), 15 g of trisodium phosphate(Na3PO4), and 1 L of distilled or deionized water.6.3 Deionized or Distilled Water, conforming to Specifica-tion D1193, Type IV.6.4 Oxygen, conforming to Federal Specification BB-0-925,Type I or oxygen of 99.5 % purity. Oxygen of higher puritymay be used if desi
37、red.7. Safety Precautions7.1 Nitric Acid:Warning! Harmful by inhalation, skin contact, and ifswallowed.Although not combustible, is a powerful oxidizing agent,which may cause combustible materials to ignite.Wear appropriate NIOSH-approved respirator, chemical re-sistant gloves (Butyl rubber), safety
38、 goggles.7.2 Sodium Hydroxide:Warning!Harmful by inhalation, skin contact, and if swal-lowed.Use adequate ventilation.Wear face shield, lab coat, rubber apron.Store away from strong acids7.3 Oxygen:Warning!Oxygen vigorously accelerates combustion.Keep oil and grease away. Do not use oil or grease on
39、regulators, gages, or control equipment.11Catalog No. 45-11311 available from Superpressure, Inc., Silver Spring, Md.20910 or equivalent has been found satisfactory.12Catalog No. 45-19123 available from Superpressure, Inc., Silver Spring, Md.20910 or equivalent has been found satisfactory.13Catalog
40、No. 45-19210 available from Superpressure, Inc., Silver Spring, Md.20910 or equivalent has been found satisfactory.14Type B Reaction Vessel Catalog No. 41-12555, available from Superpressure,Inc., Silver Spring, Md. 20910 or equivalent will meet these requirements.15ThermocoupleAssembly Catalog No.
41、45-17620 available from Superpressure,Inc. or equivalent can be used.16Heating Jacket, Catalog No. 43-12113 available from Superpressure, Inc., orequivalent can be used.17Strip chart recorders available from Honeywell, Inc., 2701 4th Ave., Minne-apolis, Minn. 55408 or equivalent can be used.18Catalo
42、g No. 9800, available from Corning Glass Works, Houghton Park,Corning, NY 14830 or equivalent can be used.19Catalog No. 9820 available from Corning Glass Works, Houghton Park,Corning, NY 14830 or equivalent has been found satisfactory.20Catalog No. 15-21AF1HM4-T available from High Pressure Equipmen
43、t Co.,1222 Linden Ave., Erie, PA. 16505 or equivalent has been found satisfactory.FIG. 3 Inner Reaction Vessel StopperG72/G72M 093Use only with equipment conditioned for oxygen service bycarefully cleaning to remove oil, grease, and other combus-tibles.Keep combustibles away from oxygen and eliminat
44、e ignitionsources.Keep surfaces clean to prevent ignition or explosion, or both,on contact with oxygen.Always use a pressure regulator. Release regulator tensionbefore opening cylinder valve.All equipment and containers used must be suitable andrecommended for oxygen service.Never attempt to transfe
45、r oxygen from cylinder in which it isreceived to any other cylinder. Do not mix gases in cylinders.Do not drop cylinder. Make sure cylinder is secure at alltimes.Keep cylinder closed when not in use.Stand away from outlet when opening cylinder valve.For technical use only. Do not use for inhalation
46、purposes.Keep cylinder out of sun and away from heat.Keep cylinder from corrosive environment.Do not use cylinder without labelDo not use dented or damaged cylinders.7.3.1 See Compressed Gas Association booklets G-4 andG-4.1 for details of safe practice in the use of oxygen.8. Procedure8.1 Clean all
47、 components of the system as follows:8.1.1 Soak glass parts in chromic acid cleaning solution,rinse in distilled water, and dry.8.1.2 Clean stainless steel components by immersing in analkaline cleaner (see 6.2) for a minimum of 15 min at 20 to 35C. Follow the immersion with a thorough rinse in runn
48、ing tapwater, followed by a thorough rinse in distilled or deionizedwater. Perform a water break test during the rinsing step toverify that organic material has been removed. Blow dry withclean, dry, oil-free nitrogen to remove the excess water, placein an oven at 52 to 66C until free of water. Comp
49、onents maybe cleaned using any process that will produce a cleanlinesslevel at least as good as the level provided by the aboveprocess. Follow Practice G93 or ASTM Manual SeriesMNL 36 recommended procedures.8.2 Weigh out a 0.20 6 0.03-g sample, either in liquid orsolid form, into the sample holder.8.3 Assemble equipment as shown in Fig. 1 and Fig. 2, andas directed by the reaction vessel manufacturer.8.4 Flush the system twice with oxygen, meeting the re-quirements of 5.1, by pressurizing the system to 5.0 MPa (725psi) and releasin
