1、Designation: G145 08 (Reapproved 2016)Standard Guide forStudying Fire Incidents in Oxygen Systems1This standard is issued under the fixed designation G145; 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 () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers procedures and material for examin-ing fires in oxygen systems for the purposes of identifyingpotential causes and
3、preventing recurrence.1.2 This guide is not comprehensive. The analysis of oxy-gen fire incidents is not a science, and definitive causes havenot been established for some events.1.3 The procedures and analyses in this guide have beenfound to be useful for interpreting fire events, for helpingidenti
4、fy potential causes, and for excluding other potentialcauses. The inclusion or omission of any analytical strategy isnot intended to suggest either applicability or inapplicability ofthat method in any actual incident study.NOTE 1Although this guide has been found applicable for assistingqualified t
5、echnical personnel to analyze incidents, each incident is uniqueand must be approached as a unique event. Therefore, the selection ofspecific tactics and the sequence of application of those tactics must beconscious decisions of those studying the event.NOTE 2The incident may require the formation o
6、f a team to providethe necessary expertise and experience to conduct the study. The personnelanalyzing an incident, or at least one member of the team, should know theprocess under study and the equipment installation.1.4 WarningDuring combustion, gases, vapors, aerosols,fumes, or combinations there
7、of, are evolved, which may bepresent and may be hazardous to people. Caution Adequateprecautions should be taken to protect those conducting astudy.1.5 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 st
8、andard 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:2E620 Practice for Reporting Opinions of Scientific or Tech-nical ExpertsE678 Practice for Evaluation of Scientific or Techni
9、cal DataE860 Practice for Examining And Preparing Items That AreOr May Become Involved In Criminal or Civil LitigationE1020 Practice for Reporting Incidents that May InvolveCriminal or Civil LitigationE1138 Terminology for Technical Aspects of Products Li-ability Litigation (Withdrawn 1995)3E1188 Pr
10、actice for Collection and Preservation of Informa-tion and Physical Items by a Technical InvestigatorE1459 Guide for Physical Evidence Labeling and RelatedDocumentationE1492 Practice for Receiving, Documenting, Storing, andRetrieving Evidence in a Forensic Science LaboratoryG63 Guide for Evaluating
11、Nonmetallic Materials for Oxy-gen ServiceG88 Guide for Designing Systems for Oxygen ServiceG93 Practice for Cleaning Methods and Cleanliness Levelsfor Material and Equipment Used in Oxygen-EnrichedEnvironmentsG94 Guide for Evaluating Metals for Oxygen ServiceG114 Practices for Evaluating the Age Res
12、istance of Poly-meric Materials Used in Oxygen ServiceG124 Test Method for Determining the Combustion Behav-ior of Metallic Materials in Oxygen-Enriched Atmo-spheresG126 Terminology Relating to the Compatibility and Sensi-tivity of Materials in Oxygen Enriched AtmospheresG128 Guide for Control of Ha
13、zards and Risks in OxygenEnriched Systems1This 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 Oct. 1, 2016. Publi
14、shed October 2016. Originallyapproved in 1996. Last previous edition approved in 2008 as G145 08. DOI:10.1520/G0145-08R16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, ref
15、er to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12.2 Compressed Gas Association (CGA) Stan
16、dards:4G-4.4 Industrial Practices for Gaseous Oxygen Transmissionand Distribution Piping SystemsG-4.8 Safe Use of Aluminum Structured Packing for Oxy-gen Distillation2.3 National Fire Protection Association (NFPA) Standard:5NFPA 53 Fire Hazards in Oxygen Enriched AtmospheresNFPA 921 Guide for Fire a
17、nd Explosion Investigations2.4 Occupational Safety and Health Act:6OSHA Process Safety Management Compliance Manual2.5 ASTM Adjuncts:Video: Oxygen Safety73. Terminology3.1 DefinitionsSee Guides G63, G94, and G128 for theterms listed in this section.3.1.1 oxygen compatibility, (also oxidant compatibi
18、lity),nthe ability of a substance to coexist with both oxygen anda potential source(s) of ignition at an expected pressure andtemperature with a magnitude of risk acceptable to the user.3.1.2 qualified technical personnel, npersons such asengineers and chemists who, by virtue of education, training,
19、or experience, know how to apply the physical and chemicalprinciples involved in the reactions between oxygen and othermaterials.3.1.3 oxygen-enriched, adja fluid (gas or liquid) mixturecontaining more than 25 mole % oxygen.3.2 Definitions of Terms Specific to This Standard:3.2.1 incident, nan ignit
20、ion or fire, or both, that is bothundesired and unanticipated, or an undesired and unanticipatedconsequence of an ignition or fire that was anticipated.3.2.2 direct incident cause, nthe mechanical or thermody-namic event (such as breakage of a component or near-adiabatic compression), the physicoche
21、mical property (such asheat of combustion), the procedure (such as a valve openingrate), or any departure(s) from the intended state of any ofthese items, that leads directly to ignition or fire, or both.3.2.3 fractional evaporation, nthe continuous evaporationof a quantity of liquid that results in
22、 a progressive increase inthe concentration of a less-volatile constituent(s).3.2.4 Contaminant, nunwanted molecular or particulatematter that could adversely affect or degrade the operation, life,or reliability of the systems or components upon which itresides.3.2.5 Contamination, n(1) the amount o
23、f unwanted mo-lecular non-volatile residue (NVR) or particulate matter in asystem; (2) the process or condition of being contaminated.DiscussionContamination and cleanliness are opposingproperties: increasing cleanliness implies decreasing contami-nation.4. Summary of Guide4.1 Following a fire incid
24、ent in an oxygen-enrichedatmosphere, the equipment, operating procedures, and area areconsidered in light of other incidents, potential contributingfactors, suggested analytical strategies, and demonstrated labo-ratory results. The goal is to determine direct cause(s) of theincident in order to prev
25、ent a recurrence.5. Significance and Use5.1 This guide helps those studying oxygen system inci-dents to select a direct cause hypothesis and to avoid conclu-sions based on hypotheses, however plausible, that haveproven faulty in the past.6. Abstract6.1 A series of possible causes and common scenario
26、s aredescribed to assist those seeking to understand incidents inoxygen-enriched atmospheres. Many easily misinterpreted fac-tors are described to help avoid faulty conclusions. Severalsuspected but unproven incident scenarios are described. Selectlaboratory data are presented to support assertions
27、about directcauses of incidents.7. Direct-Cause Analysis7.1 In this guide, the direct cause of an incident is themechanical or thermodynamic event (such as breakage of acomponent or near-adiabatic compression), the physicochemi-cal property (such as heat of combustion), the procedure (suchas a valve
28、 opening rate), or any departure(s) from the intendedstate of any of these items, that leads directly to ignition or fire,or both. A fire might also be the result of a financial decision,worker skill, or manufacturing processall of which can beviewed as causesbut such factors are addressed more prop
29、-erly in a system hazard review. It is noteworthy that some firesare anticipated and the risks (whether human or economic) areaddressed by such things as shielding (for example, to controlhuman risk) or acceptance (for example, to address economicrisk). In these cases, a fire is not an “incident” un
30、less someaspect of the event exceeded expectations the initial parameters(for example, the shielding did not provide the expectedcontainment, or the cost exceeded projections). This guideseeks to identify the material choice, equipment design, assem-bly procedure, or other factor that led directly t
31、o the fireandmore specifically, to distinguish the physical object or actionthat caused the fire to start, to continue, or to be injurious ordestructive. Remedial actions are found in other documentssuch as Guides G63, G88, and G94, and Practice G93, as wellas NFPA 53, CGA G-4.4, and G-4.8, OSHA Pro
32、cess SafetyManagement Compliance Manual, and others.7.2 ExampleThe direct cause of an incident may beconcluded to be the use of an incompatible material, forexample, a polyacetyl component was installed when a mate-rial such as PTFE (polytetrafluoroethylene) or CTFE (chloro-trifluoroethylene) was pr
33、eferred. The direct cause was not that4Available from Compressed Gas Association (CGA), 4221 Walney Rd., 5thFloor, Chantilly, VA 20151-2923, http:/.5Available from National Fire Protection Association (NFPA), 1 BatterymarchPark, Quincy, MA 02169-7471, http:/www.nfpa.org.6Available from Occupational
34、Safety and Health Administration (OSHA), 200Constitution Ave., NW, Washington, DC 20210, http:/www.osha.gov.7Available from ASTM Customer Service, 100 Barr Harbor Drive, WestConshohocken, PA 19428-2959. Request Adjunct ADJG0088.G145 08 (2016)2the budget was inadequate to cover the cost of PTFE; nor
35、thatspecific frictional properties of polyacetyl were required formechanical purposes; nor that an incorrect part was installed inerror. Note that in this example, PTFE and CTFE might beneeded to prevent or cope with ignition and fire, but that theymight introduce non-fire-related issues such as los
36、s of me-chanical strength or production of toxic decomposition prod-ucts when exposed to heat of compression.8. Elements of a Study8.1 OverviewThe study of an oxygen incident typicallybegins (preferably promptly) after the event has concluded.The fire is extinguished and any safety requirements orim
37、mediate needs are addressed (treating injuries, returningsystems to a safe state, and so forth). Then the investigator canbegin to document the event, to preserve the artifacts, and todetect how they may have been altered or compromised by theevent and follow-up activities. Although many of these st
38、epsare itemized here, the intent of this guide is not to specify howor in what order they should be conducted. Rather, informationis offered about certain procedures that have been effective inthe past, as well as some that have led to faulty conclusions.Typically, good scientific and laboratory ski
39、lls are useful andadequate. Forensic skills and procedures can be helpful inmany cases, but may not be practical in all. For example, theforensic Guide E1459 can assist with managing post-incidentartifacts, and related Practices E1492, E620, E678, E860,E1020, and E1188, as well as Terminology E1138,
40、 may haveother uses. However, when a forensic approach is neededbecause a legal action is involved, the insights in this guidemay effectively supplement it.8.2 DocumentationUrgent post-incident efforts include:photographing or videotaping the site and any damaged equip-ment; obtaining system drawing
41、s, supporting design analysis,process hazards analysis, and any other hazard-evaluationmaterials; interviewing persons knowledgeable about thesystem, operating procedures and the events before, during,and after the fire; collecting specimens, operating logs, andrelated information; and preliminary f
42、ormulation and testing ofhypotheses.8.3 AnalysisThe principal effort in a study will be analysisof the data and artifacts. This may require further examinationof the equipment and records, laboratory study of selecteditems, and perhaps even laboratory simulation of the incident.8.4 Completion of Stu
43、dyAn incident study is completewhen the qualified technical personnel involved in the studyconclude that the event is understood.8.4.1 An incident might be understood adequately when aconclusion has been drawn about the direct cause of the event.The following examples show the distinction between di
44、rectcauses and causes that are not physicochemical or thermody-namic events.8.4.1.1 Example 1A substantial amount of hydrocarbonoil was introduced into a system just before an incident. Thissingle factor may be identified as the direct cause of the fire.Any reasons for introducing the lubricant may
45、be important toa new hazard review, but are not the direct cause of the fire.Prevention can focus on cleanliness. Initiating Event: ignitionof an incompatible oil. Direct Cause: contamination of thesystem.8.4.1.2 Example 2Records may show that a componentbroke and produced a rub in a piece of machin
46、ery just beforean incident. This factor alone can ignite a fire and could beidentified as the direct cause. If the component broke becauseit contained a flaw, the flaw might be determined to be thedirect cause. However, if the part was selected because itoffered economy, then the direct cause is sti
47、ll the inadequatepartnot a misguided effort to economize. Prevention in thiscase can focus on component quality. Initiating Event: frictionduring the rub. Direct Cause: Mechanical failure.8.4.1.3 Example 3Deviation from an important operatingpractice, such as first equalizing downstream pressure wit
48、h abypass valve before opening a quick-opening valve, may beestablished as the direct cause of a fire. The reasons fordeparting from mandated practice are important, but they arenot the direct cause. Here, prevention can focus on followingstandard operating procedures. Initiating Event: approximatel
49、yadiabatic compression. Direct Cause: incorrect operation.8.4.2 An incident might be understood adequately when aconservative tactic has been identified that would have pre-vented or safely managed the event.8.4.2.1 Example 1If an item of machinery cannot employoxygen-compatible materials because they compromise itsoperating economy, and it becomes the site of a fire and injuressomeone, then the event may be understood adequately (re-garding preventing recurrence of injury rather than fire) wheninadequate shielding or inadequate mechanical
