1、Designation: G 128 02 (Reapproved 2008)Standard Guide forControl of Hazards and Risks in Oxygen Enriched Systems1This standard is issued under the fixed designation G 128; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、 last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers an overview of the work of ASTMCommittee G-4 on Compatibility and Sensitivity of Materialsin Oxygen
3、-Enriched Atmospheres. It is a starting point forthose asking the question: “Are there any problems associatedwith my use of oxygen?” An introduction to the uniqueconcerns that must be addressed in the handling of oxygen.Theprincipal hazard is the prospect of ignition with resultant fire,explosion,
4、or both. This hazard requires design considerationsbeyond those that apply to all systems, such as adequatestrength, corrosion resistance, fatigue resistance, and pressuresafety relief.1.2 This guide also lists several of the recognized causes ofoxygen system fires and describes the methods availabl
5、e toprevent them. Sources of information about the oxygen hazardand its control are listed and summarized. The principal focusis on Guides G 63, G 88, Practice G93, and Guide G94.Useful documentation from other resources and literature isalso cited.NOTE 1This guide is an outgrowth of an earlier (198
6、8) CommitteeG-4 videotape adjunct entitled Oxygen Safety and a related paper byKoch2that focused on the recognized ignition source of adiabaticcompression as one of the more significant but often overlooked causes ofoxygen fires. This guide recapitulates and updates material in thevideotape and pape
7、r.1.3 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. For specific
8、precautionary statements see Sections 8 and 11.NOTE 2ASTM takes no position respecting the validity of anyevaluation methods asserted in connection with any item mentioned in thisguide. Users of this guide are expressly advised that determination of thevalidity of any such evaluation methods and dat
9、a and the risk of use ofsuch evaluation methods and data are entirely their own responsibility.2. Referenced Documents2.1 ASTM Standards:3G63 Guide for Evaluating Nonmetallic Materials for Oxy-gen ServiceG88 Guide for Designing Systems for Oxygen ServiceG93 Practice for Cleaning Methods and Cleanlin
10、ess Levelsfor Material and Equipment Used in Oxygen-EnrichedEnvironmentsG94 Guide for Evaluating Metals for Oxygen ServiceG 126 Terminology Relating to the Compatibility and Sen-sitivity of Materials in Oxygen Enriched AtmospheresG 128 Guide for Control of Hazards and Risks in OxygenEnriched Systems
11、2.2 ASTM Adjuncts:Video: Oxygen Safety42.3 ASTM CHETAH Program:CHETAH Chemical Thermodynamic and Energy ReleaseEvaluation52.4 Compressed Gas Association (CGA) Standards:6G-4.1 Cleaning Equipment for Oxygen ServiceG-4.4 Industrial Practices for Gaseous Oxygen Transmis-sion and Distribution Piping Sys
12、tems1This guide is under the jurisdiction ofASTM Committee G04 on Compatibilityand Sensitivity of Materials in Oxygen Enriched Atmospheres and is the directresponsibility of Subcommittee G04.02 on Recommended Practices.Current edition approved Sept. 1, 2008. Published October 2008. Originallyapprove
13、d in 1995. Last previous edition approved in 2002 as G 12895(2002)1.2Koch, U. H., “Oxygen System Safety,” Flammability and Sensitivity ofMaterials In Oxygen-Enriched Atmospheres , Vol 6,ASTM STP1197,ASTM, 1993,pp. 349359.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact
14、 ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from ASTM International Headquarters. Order Adjunct No-.ADJG0088.5Available from ASTM Headquarters, 100 Barr Harbor Drive, West C
15、onsho-hocken, PA 19428, Order # DSC 51C, Version 7.2.6Available from Compressed Gas Association (CGA), 4221 Walney Rd., 5thFloor, Chantilly, VA 20151-2923, http:/.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.2.5 European Industria
16、l Gas Association (EIGA) Stan-dards:733/97/E Cleaning of Equipment for Oxygen Service2.6 National Fire Protection Association (NFPA) Stan-dards:850 Standard for Bulk Oxygen Systems at Consumer Sites51 Standard for the Design and Installation of Oxygen-FuelGas Systems for Welding, Cutting and Allied
17、Processes53 Recommended Practice on Material, Equipment, andSystems Used in Oxygen Enriched Atmospheres99 Standard for Health Care Facilities2.7 Military Specifications:9MIL-PRF-27617 Performance Specification, Grease, Air-craft and Instrument, Fuel and Oxidizer ResistantDOD-L-24574 (SH) Military Sp
18、ecification, LubricatingFluid for Low and High Pressure Oxidizing Gas Mixtures2.8 NASA Documents:10KSC 79K22280 Specification for 1,000-GPM LO2PumpBearings3. Terminology3.1 Definitions See Terminology G 126 for the termslisted in this section.3.1.1 autoignition temperature (AIT), nthe lowest tem-per
19、ature at which a material will spontaneously ignite in anoxygen-enriched atmosphere under specific test conditions.3.1.2 hazard, nsource of danger; something that couldharm persons or property.3.1.2.1 DiscussionThe magnitude of a hazard relates tothe severity of the harm it could cause.3.1.3 ignitio
20、n temperature, nthe temperature at which amaterial will ignite in an oxidant under specific test conditions.3.1.4 impact-ignition resistance, nthe resistance of a ma-terial to ignition when struck by an object in an oxygen-enriched atmosphere under a specific test procedure.3.1.5 nonmetal, nany mate
21、rial, other than a metal, non-polymeric alloy, or any composite in which the metalliccomponent is not the most easily ignited component and forwhich the individual constituents cannot be evaluated indepen-dently, including ceramics, such as glass; synthetic polymers,such as most rubbers, thermoplast
22、ics, and thermosets; andnatural polymers, such as naturally occurring rubber, wood,and cloth. nonmetallic, adj.3.1.6 oxidant compatibility, nthe ability of a substance tocoexist at an expected pressure and temperature with both anoxidant and a potential source(s) of ignition within a riskparameter a
23、cceptable to the user.3.1.7 oxygen-enriched, adjcontaining more than 25 molpercent oxygen.3.1.7.1 DiscussionOther standards such as those pub-lished by NFPA and OSHA differ from the definition in theirspecification of oxygen concentration.3.1.8 qualified technical personnel, npersons such asengineer
24、s and chemists who, by virtue of education, training,or experience, know how to apply the physical and chemicalprinciples involved in the reactions between oxidants and othermaterials.3.1.9 risk, nprobability of loss or injury from a hazard.3.1.9.1 DiscussionThe magnitude of a risk relates to howlik
25、ely a hazard is to cause harm. G 1284. Significance and Use4.1 The purpose of this guide is to introduce the hazards andrisks involved with the handling of oxygen, cautioning thereader about the limitations of present practices and technologyand about common hazards that often are overlooked. It the
26、nprovides an overview of the standards produced by ASTMCommittee G-4 and their uses, as well as similar documentsavailable from other knowledgeable sources. It does nothighlight standard test methods that support the use of thesepractices from this or other committees.4.2 The standards discussed her
27、e focus on reducing thehazards and risks associated with the use of oxygen. In general,they are not directly applicable to process reactors in which thedeliberate reaction of materials with oxygen is sought, as inburners, bleachers, or bubblers. Other ASTM Committees andproducts (such as the CHETAH
28、program5) and other outsidegroups are more pertinent for these.4.3 This guide is not intended as a specification to establishpractices for the safe use of oxygen. The documents discussedhere do not purport to contain all the information needed todesign and operate an oxygen system safely. The contro
29、l ofoxygen hazards has not been reduced to handbook procedures,and the tactics for using oxygen are not unique. Rather, theyrequire the application of sound technical judgement andexperience. Oxygen users should obtain qualified technicalexpertise to design systems and operating practices to ensuret
30、he safe use of oxygen in their specific applications.5. Summary5.1 Oxygen and its practical production and use are re-viewed. The recognized hazards of oxygen are described.Accepted and demonstrated methods to diminish those hazardsare reviewed. Applicable ASTM standards from CommitteeG-4 and how th
31、ese standards are used to help mitigate oxygensystem hazards are discussed. Similar useful documents fromthe National Fire Protection Association, the Compressed GasAssociation, and the European Industrial Gas Association alsoare cited.6. Oxygen6.1 Oxygen is the most abundant element, making up 21 %
32、of the air we breathe and 55 % of the earths crust. It supportsplant and animal life. Oxygen also supports combustion, causesiron to rust, and reacts with most metals. Pure oxygen gas iscolorless, odorless, and tasteless. Liquid oxygen is light blueand boils at 183 C (297 F).7Available from European
33、 Industrial GasAssociation, Publication de la SoudureAutogene, 32 Boulevard de la Chapelle, 75880 Paris Cedex 18, France.8Available from National Fire Protection Association (NFPA), 1 BatterymarchPark, Quincy, MA 02169-7471, http:/www.nfpa.org.9Available from Standardization Documents Order Desk, Bl
34、dg. 4 Section D, 700Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.10Available from NASA, Engineering Documentation Center, John F. KennedySpace Center, FL 32899.G 128 02 (2008)26.2 Oxygen has many commercial uses. For example, it isused in the metals industry for steel making, flame cutting
35、, andwelding. In the chemical industry it is used for production ofsynthetic gas, gasoline, methanol, ammonia, aldehydes, alco-hol production, nitric acid, ethylene oxide, propylene oxide,and many others. It is also used for oxygen-enriched fuelcombustion and wastewater treatment. For life support s
36、ystemsit is used in high-altitude flight, clinical respiratory therapy oranesthesiology, and emergency medical and fire service res-cues.7. Production and Distribution7.1 Most oxygen is produced cryogenically by distillingliquid air. The recent demand for ultrahigh purity within thesemiconductor ind
37、ustry has led to much more thorough distil-lation of cryogenic oxygen. Further, noncryogenic productionhas become significant in recent years. The principal differenceamong these sources of oxygen is the resulting oxygen purity.The hazards of oxygen are affected greatly by purity and, ingeneral, hig
38、her purity is more hazardous However, fire eventscan and do occur in any oxygenenriched atmosphere.7.2 Cryogenic ProductionCryogenically produced oxy-gen is distilled in a five-step process in which air is: (1) filteredto remove particles; (2) compressed to approximately 700 kPa(100 psig) pressure;
39、(3) dried to remove water vapor andcarbon dioxide; (4) cooled to 160 C (256 F) to liquefy itpartially; and (5) distilled to separate each component gas. Theend products are oxygen, nitrogen, and inert gases such asargon and neon; the principal secondary products are nitrogenand argon. Commercial oxy
40、gen is produced to a minimum99.5 % purity, but typical oxygen marketed today is morelikely to be near 99.9 % purity.7.2.1 For high-volume bulk users, such as steel or chemicalplants, the oxygen plant is often adjacent to the users facility,and gas is delivered by pipeline at low to medium pressures,
41、usually 700 to 5500 kPa (100 to 800 psig).7.2.2 Cryogenic liquid oxygen is delivered by trailer tolarge-volume users, who utilize storage tanks and equipment topump, vaporize, and distribute the gas (Fig. 1).7.2.3 Most users buy oxygen in small amounts, usually in20-MPa or 2500-psig cylinders, and u
42、se it directly from thecylinders or through manifolds and a piping distributionsystem. Usually, the pressure is reduced with a regulator at thecylinder or manifold.7.3 Ultrahigh-Purity OxygenThere are a few markets thatrequire high- and ultrahigh-purity oxygen. High-purity oxygentypically delivers 9
43、9.99 % purity, whereas the demands of thesemiconductor industry have resulted in the marketing of99.999 % purity oxygen.7.4 Noncryogenic ProductionNoncryogenic oxygen pro-duction processes include pressure swing adsorption (PSA),vacuum swing adsorption (VSA), and membrane separation. Ingeneral, thes
44、e methods produce oxygen less pure than cryo-genically produced oxygentypically 97 %, with the balancebeing nitrogen, argon, and carbon dioxide. However, theseprocesses use less power and offer a cost advantage forhigh-volume users who do not need higher purity.The equipment for these systems is typ
45、ically large and islocated on site. However, small medical-oxygen generatorsused in the home also are included in this category.8. Hazards and Risks8.1 How can oxygen be hazardous? It is all around us. Itsupports life and is used to support or resuscitate a person withoxygen deficiency (hypoxemia).
46、It may have been used in acommon familiar system for years without a problem. Could itbe that oxygen is not hazardous? No, oxygen presents definitehazards.8.2 Despite its apparent innocence in many instances, oxy-gen is a serious fire hazard. It makes materials easier to igniteand their subsequent c
47、ombustion more intense, more complete,and more explosive than in air alone. Fires in air, which containjust 21 % oxygen, are common. The injuries, loss of life, andproperty damage they cause can be devastating. Fires andexplosions that occur in oxygen-enriched atmospheres can beeven more devastating
48、, whether involving a patient in anoxygen-enriched environment or someone at an industrial sitethat uses oxygen.8.3 Oxygen is not flammable by itself, but it supportscombustion. In most instances, a fire occurs when an oxidantsuch as oxygen is combined chemically with a fuel. Hence,although oxygen i
49、s not flammable, its contribution to theproduction of fire and heat is otherwise comparable to that ofthe fuel. If there is no fuel, there is no fire. If there is nooxidant, there is no fire.FIG. 1 High-volume Oxygen Users Buy the Gas in Bulk, Storing Itin an Adjacent FacilityG 128 02 (2008)38.4 The ability of an oxygen-enriched atmosphere to sup-port and enhance combustion after ignition occurs is its hazard.The risk to people and property that accompanies this hazard isvariable. Sometimes the human risk is grave; sometimes theeconom
