1、Designation: G126 16Standard Terminology Relating to theCompatibility and Sensitivity of Materials in OxygenEnriched Atmospheres1This standard is issued under the fixed designation G126; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi
2、on, the year of 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 terminology defines terms related to the compat-ibility and sensitivity of materials in oxygen en
3、riched atmo-spheres. It includes those standards under the jurisdiction ofASTM Committee G04.1.2 The terminology concentrates on terms commonly en-countered in and specific to practices and methods used toevaluate the compatibility and sensitivity of materials inoxygen. This evaluation is usually pe
4、rformed in a laboratoryenvironment, and this terminology does not attempt to includelaboratory terms.2. Referenced Documents2.1 ASTM Standards:2D2863 Test Method for Measuring the Minimum OxygenConcentration to Support Candle-Like Combustion ofPlastics (Oxygen Index)G63 Guide for Evaluating Nonmetal
5、lic Materials for Oxy-gen ServiceG72 Test Method for Autogenous Ignition Temperature ofLiquids and Solids in a High-Pressure Oxygen-EnrichedEnvironmentG74 Test Method for Ignition Sensitivity of NonmetallicMaterials and Components by Gaseous Fluid ImpactG86 Test Method for Determining Ignition Sensi
6、tivity ofMaterials to Mechanical Impact in Ambient Liquid Oxy-gen and Pressurized Liquid and Gaseous Oxygen Envi-ronmentsG88 Guide for Designing Systems for Oxygen ServiceG93 Practice for Cleaning Methods and Cleanliness Levelsfor Material and Equipment Used in Oxygen-EnrichedEnvironmentsG94 Guide f
7、or Evaluating Metals for Oxygen ServiceG114 Practices for Evaluating the Age Resistance of Poly-meric Materials Used in Oxygen ServiceG120 Practice for Determination of Soluble Residual Con-tamination by Soxhlet ExtractionG121 Practice for Preparation of Contaminated Test Cou-pons for the Evaluation
8、 of Cleaning AgentsG122 Test Method for Evaluating the Effectiveness ofCleaning AgentsG124 Test Method for Determining the Combustion Behav-ior of Metallic Materials in Oxygen-Enriched Atmo-spheresG125 Test Method for Measuring Liquid and Solid MaterialFire Limits in Gaseous OxidantsG128 Guide for C
9、ontrol of Hazards and Risks in OxygenEnriched SystemsG131 Practice for Cleaning of Materials and Components byUltrasonic TechniquesG136 Practice for Determination of Soluble Residual Con-taminants in Materials by Ultrasonic ExtractionG144 Test Method for Determination of Residual Contami-nation of M
10、aterials and Components by Total CarbonAnalysis Using a High Temperature CombustionAnalyzerG145 Guide for Studying Fire Incidents in Oxygen Systems3. Terminology3.1 Definitions:aging, nthe exposure of a material to stress, such stress ofwhich may include time, pressure, temperature, abrasion,ionizin
11、g radiation, light, impact with gas or particles, tensileor compressive force (either static or cyclic), or any otherfeature that may be present individually or in combination.G114accelerated aging, na type of artificial aging whereby theeffect of prolonged exposure during service is stimulated byag
12、ing at elevated temperature. G114artificial aging, naging in which a stress variable is outsidethe domain of exposure that a material might see in acomponent for oxygen service or in which an alternativemechanism is used to produce an effect that simulates theresults of natural aging.1This terminolo
13、gy is under the jurisdiction of ASTM Committee G04 onCompatibility and Sensitivity of Materials in Oxygen Enriched Atmospheres and isthe direct responsibility of Subcommittee G04.02 on Recommended Practices.Current edition approved Dec. 15, 2016. Published January 2017. Originallyapproved in 1994. L
14、ast previous edition approved in 2008 as G126 00(2008).DOI: 10.1520/G0126-16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page ont
15、he ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDeve
16、lopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1DISCUSSIONThe degree of artificiality may vary on a large scale.Anexample of mild artificiality is exposure of a material to a greaterpressure than it ex
17、periences in the use condition. An example ofextreme artificiality is the use of sandpaper to increase a materialssurface roughness to simulate particle-impact abrasion that occurs inthe use condition. A high degree of artificiality affects the strength ofconclusion that can be drawn, because it may
18、 be difficult to relate theresults to the use condition. Artificial aging that accelerates naturalaging but does not alter the resulting effect is preferred. G114autoignition temperature (AIT), nthe lowest temperatureat which a material will spontaneously ignite in an oxygen-enriched atmosphere unde
19、r specific test conditions.G63, G72, G94, G128average regression rate (Regression Rate of the MeltingInterface RRMI), nthe average rate at which the meltinginterface advances along the test sample length as melting ofthe test sample occurs. G124blank, nthe contamination level of a fluid when the tes
20、tcoupon is omitted.DISCUSSIONSometimes referred to as the “background level.”G121burn length, nthe burn length is the length of the sample thathas been consumed by burning.DISCUSSIONThe burn length is determined by subtracting thepost-test sample length from the pretest sample length (which does not
21、include the promoter length or the region used by the test samplesupport). G124characteristic elements, nthose factors that must be presentfor an ignition mechanism to be active in an oxygen-enriched atmosphere. The more characteristic elements pres-ent for a particular ignition mechanism, the more
22、active thatmechanism is. G88cleaning effectiveness factor (CEF), nthe fraction of con-taminant removed from an initially contaminated test cou-pon as determined by gravimetric techniques. G122cleanliness, nthe degree to which an oxygen system is freeof contaminant.DISCUSSIONCleanliness and contamina
23、tion are opposing properties:increasing cleanliness implies decreasing contamination. G93contaminant (contamination), nunwanted molecular, non-volatile residue (NVR), or particulate matter, or combina-tions thereof, that could adversely affect or degrade theoperation, life, or reliability of the sys
24、tems or componentsupon which it resides.DISCUSSIONContamination and cleanliness are opposing properties:increasing cleanliness implies decreasing contamination. G93, G120,G121, G131, G136, G144, G145contaminate, va process of applying contaminant. (non-volatile residue (NVR) and/or particulate matte
25、r). G131,G136, G120, G121control coupon (witness coupon),na coupon made from thesame material and prepared in exactly the same way as thetest coupons which is used to verify the validity of themethod or part thereof.DISCUSSIONIn practice, the control coupon is contaminated in thesame manner as the t
26、est coupons and is subjected to the identicalcleaning procedure. G120, G121, G131degas, vthe process of removing gases from a liquid. G131,G136direct incident cause, nthe mechanical or thermodynamicevent (such as breakage of a component or near-adiabaticcompression), the physicochemical property (su
27、ch as heat ofcombustion), the procedure (such as a valve opening rate), orany departure(s) from the intended state of any of theseitems, that leads directly to ignition, or fire, or both. G145direct oxygen service, nservice in contact with oxygen-enriched atmosphere during normal operations.DISCUSSI
28、ONExamples are oxygen compressor piston rings or con-trol valve seats. G63, G88, G94energy threshold, nthe highest impact energy level at agiven pressure for which the passing criteria have been met.G86exemption pressure, nthe maximum pressure for an engi-neering alloy at which there are no oxygen v
29、elocity restric-tions (from CGA 4.4 and EIGA doc IGC13). G94fibers, nparticulate matter with a length of 100 m or greaterand a length-to-width ratio of 10 to 1 or greater. G93fire limit, nthe threshold limit conditions that will justsupport self-sustained burning of a material under a combi-nation o
30、f specified conditions and at least one variableparameter. (Typically oxidant concentration, diluent nature,pressure, temperature, geometry, flow or flame parametersetc.) G125flammable material, na material that is able to ignite anddemonstrate self-sustained burning per specific test methodcriteria
31、 considering configurational, environmental, and pro-moter energy conditions (example: Oxidizer%, P, T, etc.).DISCUSSIONIt is noteworthy that a materials flammability inoxygen is highly-dependent on multiple factors (configuration,environment, promoter energy, etc.) and caution is advised to conside
32、rthese factors when evaluating a materials flammability in a givenoxygen application. G124fractional evaporation, nthe continuous evaporation of thequantity of liquid that results in a progressive concentrationof a less-volatile constituent(s). G145galling, na condition whereby excessive friction be
33、tweenhigh spots results in localized welding with subsequentsplitting and a further roughening of rubbing surfaces of oneor both of two mating parts. G88gaseous fluid impact-igintion resistance, nthe resistance ofa material to ignition when struck by rapidly compressedhigh pressure gas in an oxygen
34、enriched atmosphere under aspecific test procedure. G63hazard, nsource of danger; something that could harmpersons or property.DISCUSSIONThe magnitude of a hazard relates to the severity of theharm it could cause. G128G126 162highest no-burn pressure, nthe highest gas pressure tested(at a specified
35、oxygen concentration and fixed sampletemperature) at which a material does not burn more thanspecific test method criteria. G124highest no-burn temperature, nthe maximum sample tem-perature (at a specified oxygen concentration and pressure)at which a material does not burn more than specific testmet
36、hod criteria. G124igniter, na material used to ignite the promoter that can burnunder an electrical influence, such as a small-diameter wire.G124ignition temperature, nthe temperature at which a materialwill ignite in an oxidant under specific test or systemconditions.DISCUSSIONThe ignition temperat
37、ure of a material in a system isrelated to the temperature measured by Test Method G72 (AIT), but isalso a function of system pressure, configuration and operation, andthermal history of the material. G88, G128ignition mechanisms, nspecific factors (physical attributessuch as system materials, syste
38、m design, component design,component performance factors, contamination, etc. as wellas system conditions such as temperature, pressure, flowvelocities, oxygen concentration, etc.) that cause the initialfire within a system.DISCUSSIONA system designer must evaluate an oxygen-enrichedsystem for all p
39、ossible ignition mechanisms. A common ignitionmechanism for metals is particle impact. A common ignition mecha-nism for non-metals is compression heating. G88, G128incident, nan ignition or fire, or both, that is both undesiredand unanticipated, or an undesired and unanticipated conse-quence of an i
40、gnition or fire that was anticipated. G145indirect oxygen service, nservice that is not normally incontact with oxygen but which might be as a result of aforeseeable malfunction (single fault), operator error, orprocess upset. Examples: liquid oxygen tank insulation orliquid oxygen pump motor bearin
41、gs. G63, G88, G94lowest burn pressure, nthe minimum tested gas pressure (ata specified oxygen concentration and fixed sample tempera-ture) at which a material burns more than specific testmethod criteria. G124lowest burn temperature, nthe minimum tested sampletemperature (at a specified oxygen conce
42、ntration and pres-sure) at which a material burns more than specific testmethod criteria. G124maximum use pressure, nthe greatest pressure to which amaterial can be subjected as a result of a reasonablyforeseeable malfunction, operator error or process upset.G63, G94maximum use temperature, nthe gre
43、atest temperature towhich a material can be subjected as a result of a reasonablyforeseeable malfunction, operator error, or process upset.G63, G94mechanical impact, na blow delivered by a plummet thathas been dropped from a pre-established height onto a strikerpin, in contact with a sample. G86mech
44、anical impact-ignition resistance, nthe resistance of amaterial to ignition when struck by an object in an oxygen-enriched atmosphere under a specific test procedure. G63,G94, G128molecular contaminant (non-particulate contamination),nmolecular contaminants that may exist in a gaseous,liquid, or sol
45、id state and may be uniformly or nonuniformlydisturbed.DISCUSSIONMolecular contaminant may be found as a solution, anemulsion, or in the form of droplets. Molecular contaminants accountfor most of what constitutes Non-Volatile Residue (NVR). G120,G121, G136, G144natural aging, naging in which a mate
46、rial is exposed toconditions replicating those that are present in actual servicein a component for oxygen service. G114nonmetal, nany material other than a metal, non-polymericalloy, or any composite in which the metallic component isnot the most easily ignited component and for which theindividual
47、 constituents cannot be evaluated independently,including ceramics (such as glass), synthetic polymers (suchas most rubbers), thermoplastics, thermosets, and naturalpolymers (such as naturally occurring rubber, wood, andcloth.) Nonmetallic is the adjective form of this term.G63, G93, G94, G128nonvol
48、atile residue (NVR), nmolecular or particulate mat-ter remaining following the filtration and controlled evapo-ration of a solvent containing contaminants.DISCUSSIONThe size of a particle is usually defined by its greatestdimension and is specified in micrometers. NVR may be uniformly ornon-uniforml
49、y distributed as a solution, an emulsion or in the form ofdroplets. Molecular contaminants account for most of the Non-volatileResidue NVR. G120, G121, G131, G136, G144operating pressure, nthe pressure expected under normaloperating conditions. G63, G94operating temperature, nthe temperature expected undernormal operating conditions. G63, G94oxidant compatibility, nthe ability of a substance to coexistat an expected pressure and temperature with both an oxidantand a potential source(s) of ignition within a risk paramete
