1、Designation: G 128 02e1Standard 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 last revision.
2、A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEEditorial corrections were made throughout in May 2003.1. Scope1.1 This guide covers an overview of the work of ASTMCommittee G-4 on Compa
3、tibility and Sensitivity of Materialsin Oxygen-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 prosp
4、ect of ignition with resultant fire,explosion, 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
5、system fires and describes the methods available 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 G 93, and Guide G 94.Useful documentation from other resources and literature isalso cited.NO
6、TE 1This guide is an outgrowth of an earlier (1988) 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 recapitula
7、tes and updates material in thevideotape and paper.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
8、regulatory limitations prior to use. For specificprecautionary 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 t
9、hevalidity of any such evaluation methods and data and the risk of use ofsuch evaluation methods and data are entirely their own responsibility.2. Referenced Documents2.1 ASTM Standards:G 63 Guide for Evaluating Nonmetallic Materials for Oxy-gen Service3G 88 Guide for Designing Systems for Oxygen Se
10、rvice3G 93 Practice for Cleaning Methods and Cleanliness Levelsfor Material and Equipment Used in Oxygen-EnrichedEnvironments3G 94 Guide for Evaluating Metals for Oxygen Service3G 125 Test Method for Measuring Liquid and Solid Mate-rial Fire Limits in Gaseous Oxidants3G 126 Terminology Relating to t
11、he Compatibility and Sen-sitivity of Materials in Oxygen Enriched Atmospheres3G 145 Guide for Studying Fire Incidents in Oxygen Sys-tems32.2 ASTM Adjuncts:Video: Oxygen Safety42.3 ASTM CHETAH Program:CHETAH Chemical Thermodynamic and Energy ReleaseEvaluation52.4 Compressed Gas Association (CGA) Stan
12、dards:6G-4.1 Cleaning Equipment for Oxygen ServiceG-4.4 Industrial Practices for Gaseous Oxygen Transmis-sion and Distribution Piping Systems2.5 European Industrial Gas Association (EIGA) Stan-dards:71This guide is under the jurisdiction of ASTM Committee G4 on Compatibilityand Sensitivity of Materi
13、als in Oxygen- Enriched Atmospheres and is the directresponsibility of Subcommittee G04.02 on Recommended Practices.Current edition approved March 10, 2002. Published June 2002. Originallypublished as G12895. Last previous version G12895.2Koch, U. H., “Oxygen System Safety,” Flammability and Sensiti
14、vity ofMaterials In Oxygen-Enriched Atmospheres, Vol 6, ASTM STP 1197, ASTM, 1993,pp. 349359.3Annual Book of ASTM Standards, Vol 14.04.4Oxygen Safety, adjunct is available from ASTM Customer Service, 100 BarrHarbor Drive, West Conshohocken, PA 19428. Request ADJG0088.5Available from ASTM Headquarter
15、s, 100 Barr Harbor Drive, West Consho-hocken, PA 19428, Order # DSC 51C, Version 7.2.6Available from Compressed Gas Association, 4221 Walney Road, 5th Floor,Chantilly, VA 20151.7Available from European Industrial Gas Association, Publication de la SoudureAutogene, 32 Boulevard de la Chapelle, 75880
16、Paris Cedex 18, France.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.33/97/E Cleaning of Equipment for Oxygen Service2.6 National Fire Protection Association (NFPA) Stan-dards:850 Standard for Bulk Oxygen Systems at Consumer Sites5
17、1 Standard for the Design and Installation of Oxygen-FuelGas Systems for Welding, Cutting and Allied Processes53 Recommended Practice on Material, Equipment, andSystems Used in Oxygen Enriched Atmospheres99 Standard for Health Care Facilities2.7 Military Specifications:9MIL-PRF-27617 Performance Spe
18、cification, Grease, Air-craft and Instrument, Fuel and Oxidizer ResistantDOD-L-24574 (SH) Military Specification, LubricatingFluid for Low and High Pressure Oxidizing Gas Mixtures2.8 NASA Documents:10KSC 79K22280 Specification for 1,000-GPM LO2PumpBearings3. Terminology3.1 DefinitionsSee Terminology
19、 G 126 for the termslisted in this section.3.1.1 autoignition temperature (AIT), nthe lowest tem-perature 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
20、 DiscussionThe magnitude of a hazard relates tothe severity of the harm it could cause.3.1.3 ignition 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
21、an object in an oxygen-enriched atmosphere under a specific test procedure.3.1.5 nonmetal, nany material, 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 ind
22、epen-dently, including ceramics, such as glass; synthetic polymers,such as most rubbers, thermoplastics, 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 pressur
23、e and temperature with both anoxidant and a potential source(s) of ignition within a riskparameter acceptable 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 thei
24、rspecification of oxygen concentration.3.1.8 qualified technical personnel, npersons such asengineers 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, npro
25、bability of loss or injury from a hazard.G 1283.1.9.1 DiscussionThe magnitude of a risk relates to howlikely a hazard is to cause harm.4. 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 limita
26、tions of present practices and technologyand about common hazards that often are overlooked. It thenprovides 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 t
27、hat support the use of thesepractices from this or other committees.4.2 The standards discussed here 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 s
28、ought, as inburners, bleachers, or bubblers. Other ASTM Committees andproducts (such as the CHETAH 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 pur
29、port to contain all the information needed todesign and operate an oxygen system safely. The control 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 us
30、ers should obtain qualified technicalexpertise to design systems and operating practices to ensurethe 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 me
31、thods to diminish those hazardsare reviewed. Applicable ASTM standards from CommitteeG-4 and how these standards are used to help mitigate oxygensystem hazards are discussed. Similar useful documents fromthe National Fire Protection Association, the Compressed GasAssociation, and the European Indust
32、rial Gas Association alsoare cited.6. Oxygen6.1 Oxygen is the most abundant element, making up 21 %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, odor
33、less, and tasteless. Liquid oxygen is light blueand boils at 183C (297 F).6.2 Oxygen has many commercial uses. For example, it isused in the metals industry for steel making, flame cutting, andwelding. In the chemical industry it is used for production ofsynthetic gas, gasoline, methanol, ammonia, a
34、ldehydes, alco-hol production, nitric acid, ethylene oxide, propylene oxide,8Available from the National Fire Protection Association, 1 Batterymarch Park,Box 9101, Quincy, MA 02269-9101.9Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700Robbins Ave., Philadelphia, PA 19111-5
35、094, Attn: NPODS.10Available from NASA, Engineering Documentation Center, John F. KennedySpace Center, FL 32899.G12802e12and many others. It is also used for oxygen-enriched fuelcombustion and wastewater treatment. For life support systemsit is used in high-altitude flight, clinical respiratory ther
36、apy 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 industry has led to much more thorough distil-lation of cryogenic oxyg
37、en. 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, higher purity is more hazardous However, fire eventscan and do occur i
38、n 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; (3) dried to remove water vapor andcarbon dioxide; (4) cooled to 16
39、0C (256F) 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 oxygen is produced to a minimum99.5 % purity, but typical oxygen markete
40、d 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,usually 700 to 5500 kPa (100 to 800 psig).7.2.2 Cryogenic liquid oxyg
41、en 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 use it directly from thecylinders or through manifolds and a piping di
42、stributionsystem. 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 99.99 % purity, whereas the demands of thesemiconductor industry have
43、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, these methods produce oxygen less pure than cryo-genically produced oxyge
44、ntypically 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 typically large and islocated on site. However, small medical-oxygen gen
45、eratorsused 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). It may have been used in acommon familiar system for years without a
46、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 combustion more intense, more complete,and more explosive than in air
47、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, whether involving a patient in anoxygen-enriched environment or som
48、eone 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 is not flammable, its contribution to theproduction of fire and heat i
49、s otherwise comparable to that ofthe fuel. If there is no fuel, there is no fire. If there is nooxidant, there is no fire.8.4 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 theeconomic risk is severe. In these instances, the need to preventcombustion is imperative. Occasionally the risk is smallFIG. 1 High-volume Oxygen Users Buy the Gas in Bulk, Storing Itin an Adjacent
