1、Designation: G72/G72M 15Standard 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 MPa
4、1500 psi, and isintended for applicability to high pressure conditions. The testmethod, as described, is for liquids or solids with ignitiontemperature in the range from 60 to 500 C 140 to 932 F.NOTE 1Test Method G72/G72M normally utilizes samples of ap-proximately 0.20 +/- 0.03-g mass, a starting p
5、ressure of 10.3 MPa1500 psi and a temperature ramp rate of 5 C min. However, Autog-enous Ignition Temperatures (AIT) can also be obtained under other testconditions. Testing experience has shown that AIT testing of volatileliquids can be influenced by the sample pre-conditioning and the samplemass.
6、This will be addressed in the standard as Special Case 1 insubsection 8.2.2. Testing experience has also shown that AIT testing ofsolid or non-volatile liquid materials at low pressures (i.e., 2.1 MPa) canbe significantly influenced by the sample mass and the temperature ramprate. This will be addre
7、ssed in the standard as Special Case 2, insubsection 8.2.3. Since the AIT of a material is dependent on the samplemass/configuration and test conditions, any departure from the standardconditions normally used for Test Method G72/G72M testing should beclearly indicated in the test report.1.3 This te
8、st 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 requirements is de-scribed. This test method could be applied to higher pressuresand materials of higher ignition temperature. If more severerequirement
9、s or other oxidizers than those described aredesired, care must be taken in selecting an alternative safeapparatus capable of withstanding the conditions.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
10、exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith 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
11、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:2D1193 Specification for Reagent WaterE177 Practice for Use of the Terms Precision and Bias inASTM Test Me
12、thodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodG93 Practice for Cleaning Methods and Cleanliness Levelsfor Material and Equipment Used in Oxygen-EnrichedEnvironments2.2 Federal Specification:BB-O-925 Oxygen, Technical, Gas and Liquid32.3 Other Do
13、cuments:MNL 36 Safe Use of Oxygen and Oxygen Systems: Guide-lines for Oxygen System Design, Materials, Selection,Operations, Storage, and Transportation4Compressed Gas Association Booklets G-1 and G-4.153. Summary of Test Method3.1 This autogenous ignition temperature test method isdesigned to expos
14、e solid or liquid sample material to increasingtemperature in a high-pressure reaction vessel. The reaction1This test method is under the jurisdiction of ASTM Committee G04 onCompatibility and Sensitivity of Materials in Oxygen Enriched Atmospheres and isthe direct responsibility of Subcommittee G04
15、.01 on Test Methods.Current edition approved Oct. 1, 2015. Published October 2015. Originallyapproved in 1982. Last previous edition approved in 2009 as G72/G72M 09. DOI:10.1520/G0072_G0072M-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at s
16、erviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.4AST
17、M Manual Series, Available from ASTM International, 100 Barr HarborDrive, W. Conshohocken, PA 19428.5Available from Compressed Gas Association (CGA), 4221 Walney Rd., 5thFloor, Chantilly, VA 20151-2923, http:/.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19
18、428-2959. United States1vessel (bomb), including a sample holding assembly, 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 thermocoup
19、le and recordingpotentiometer.3.2 The minimum temperature required to 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
20、 temperature is related to thesample size. A sample size is selected 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
21、the temperature isincreased, the pressure increases. No effort is made to controlthe pressure during the test. It is monitored only so that thepressure does not exceed a safe limit for the test equipment.4. Significance and Use4.1 Most organic liquids and solids will ignite in a pressur-ized oxidizi
22、ng gas atmosphere if heated to a sufficiently 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 o
23、f fire and explosion hazards in specific 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 w
24、ith the geometry of the testsystem and 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
25、 The decomposition and oxidation of some 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 ignitiontempera
26、ture.5. Apparatus5.1 Suitable components 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 isillus
27、trated in Fig. 1.5.2 Cylinder Oxygen, conforming 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, maxi-mum pressure 206.8 MPa 30 000 psi, for 6.35-mm 14-in.high-pressure
28、 tubing with a 3.18-mm 18-in. port.65.4 Compressor Pumps, diaphragm-type, air-driven.75.5 Valves, 6.35 mm 14 in., 206.8 MPa 30 000 psiworking pressure, nonrotating stem valves.85.6 Pressure Gage, 20.7 MPa 3000 psi, 216 mm 812 in.9Heise 2 or equivalent has been found satisfactory.6Catalog No. 49-1440
29、5 available from Superpressure, Inc., Silver Spring, Md.20910 or equivalent has been found satisfactory.7Catalog No. 46-14035 available from Superpressure, Inc., Silver Spring, Md.20910 or equivalent has been found satisfactory.8Catalog No. 44-13121 available from Superpressure, Inc., Silver Spring,
30、 Md.20910 or equivalent has been found satisfactory.9Model C available from Heise Bourdon Tube Co., Newton, Conn. 06740 orequivalent has been found satisfactory.FIG. 1 AIT Equipment AssemblyG72/G72M 1525.7 Connecting Tubing, Type 316 stainless steel, 6.35 mm14 in., 448.1 MPa 65 000 psi pressure rati
31、ng at 37.8 C100 F.105.8 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. 45-14311.11All connection fittings shall be of cold-drawn Type 316stainless steel, 413.7 MPa 60 000 psi maximum p
32、ressure,tubing size 6.35 mm 14 in. high-pressure and 14.3-mm916-in. insertion depth.125.9 Pressure-Relief Blowout with Rupture Discs, pressure-relief blow-out assembly, Type 316 stainless steel, 6.35 mm14 in., angle type13with 48.3 MPa 7000 psi at 22.2 C72 F rupture disks.1410Catalog No. 45-11021 av
33、ailable from Superpressure, Inc., Silver Spring, Md.20910 or equivalent has been found satisfactory.11Catalog No. 45-14311 available from Superpressure, Inc., Silver Spring, Md.20910 or equivalent has been found satisfactory.12Catalog No. 45-11311 available from Superpressure, Inc., Silver Spring, M
34、d.20910 or equivalent has been found satisfactory.13Catalog No. 45-19123 available from Superpressure, Inc., Silver Spring, Md.20910 or equivalent has been found satisfactory.14Catalog No. 45-19210 available from Superpressure, Inc., Silver Spring, Md.20910 or equivalent has been found satisfactory.
35、FIG. 2 Sample Holding AssemblyG72/G72M 1535.10 Reaction Vessel (Bomb)A suitable reaction vessel forthe test method is cylindrical, 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,
36、with a volume equal to approxi-mately 110 mL. The maximum working pressure at 427 C800 F is 82.7 MPa 12 000 psi.155.11 Thermocouple 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.1
37、65.12 Heating JacketA 230-V, 1000-W single-phase heat-ing jacket designed to fit the reaction vessel should be used.175.13 Recorder, 0 to 1000 C 0 to 2000 FA strip chartrecording pyrometer in the temperature range for the testmethod should be used.18The scale must be such that a suddenchange of 20 C
38、 36 F or more in temperature in the reactionvessel is clearly indicated.5.14 Inner Reaction VesselA borosilicate glass test tube15 by 125 mm.195.15 Sample HolderA borosilicate glass culture tube 10by 75 mm.205.16 Wire Support, fashioned from ChromelA, No. 21AWGwire.10Several turns of wire are wound
39、on a mandrel ofsufficient size so that the resulting spring-like structure fits theinner reaction vessel snugly. A loop 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 react
40、ion vessel coverand supporting the entire sample-holding assembly.215.18 Inner Reaction Vessel Stopper, fashioned from12.5-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 Analy
41、ticalReagent grade nitric acid and deionized water.6.2 Alkaline CleanerConsisting of a solution of 15 g ofsodium hydroxide (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, co
42、nforming to Federal Specification BB-0-925,Type I or oxygen of 99.5 % purity. Oxygen of higher puritymay be used if desired.7. Safety Precautions7.1 Nitric Acid:Warning! Harmful by inhalation, skin contact, and if swal-lowed.Although not combustible, is a powerful oxidizing agent,which may cause com
43、bustible materials to ignite.Wear appropriate NIOSH-approved respirator, chemical re-sistant gloves (Butyl rubber), safety 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 st
44、rong acids7.3 Oxygen:Warning! Oxygen vigorously accelerates combustion.Keep oil and grease away. Do not use oil or grease onregulators, gages, or control equipment.Use only with equipment conditioned for oxygen service bycarefully cleaning to remove oil, grease, and other combus-tibles.Keep combusti
45、bles away from oxygen and eliminate ignitionsources.Keep surfaces clean to prevent ignition or explosion, or both,on contact with oxygen.15Type B Reaction Vessel Catalog No. 41-12555, available from Superpressure,Inc., Silver Spring, Md. 20910 or equivalent will meet these requirements.16Thermocoupl
46、eAssembly Catalog No. 45-17620 available from Superpressure,Inc. or equivalent can be used.17Heating Jacket, Catalog No. 43-12113 available from Superpressure, Inc., orequivalent can be used.18Strip chart recorders available from Honeywell, Inc., 2701 4th Ave.,Minneapolis, Minn. 55408 or equivalent
47、can be used.19Catalog No. 9800, available from Corning Glass Works, Houghton Park,Corning, NY 14830 or equivalent can be used.20Catalog No. 9820 available from Corning Glass Works, Houghton Park,Corning, NY 14830 or equivalent has been found satisfactory.21Catalog No. 15-21AF1HM4-T available from Hi
48、gh Pressure Equipment Co.,1222 Linden Ave., Erie, PA. 16505 or equivalent has been found satisfactory.FIG. 3 Inner Reaction Vessel StopperG72/G72M 154Always use a pressure regulator. Release regulator tensionbefore opening cylinder valve.All equipment and containers used must be suitable andrecommen
49、ded for oxygen service.Never attempt to transfer 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 purposes.Keep cylinder out of sun and away from heat.Keep cylinder from corrosive environment.Do not use cylinder without la
