1、Designation: G 126 00Standard Terminology Relating to theCompatibility and Sensitivity of Materials in OxygenEnriched Atmospheres1This standard is issued under the fixed designation G 126; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revi
2、sion, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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
3、 enriched atmo-spheres. It includes those standards under the jurisdiction ofASTM Committee G-4.1.2 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
4、 performed in a laboratoryenvironment, and this terminology does not attempt to includelaboratory terms.2. Referenced Documents2.1 ASTM Standards:G63 Guide for Evaluating Nonmetallic Materials for Oxy-gen Service2G72 Test Method for Autogenous Ignition Temperature ofLiquids and Solids in a High-Pres
5、sure Oxygen-EnrichedEnvironment2G 74 Test Method for Ignition Sensitivity of Materials toGaseous Fluid Impact2G 86 Test Method for Determining Ignition Sensitivity ofMaterials to Mechanical Impact in Pressurized OxygenEnvironments2G88 Guide for Designing Systems for Oxygen Service2G93 Practice for C
6、leaning Methods for Material andEquipment Used in Oxygen-Enriched Environments2G94 Guide for Evaluating Metals for Oxygen Service2G114 Practice forAging Oxygen-Service Materials Prior toFlammability Testing2G 120 Practice for Determination of Soluble Residual Con-tamination in Materials and Componen
7、ts by Soxhlet Ex-traction2G 121 Practice for Preparation of Contaminated Test Cou-pons for the Evaluation of Cleaning Agents2G 122 Test Method for Evaluating the Effectiveness ofCleaning Agents2G 124 Test Method for Determining the Combustion Be-havior of Metallic Materials in Oxygen-Enriched Atmo-s
8、pheres2G 125 Test Method for Measuring Liquid and Solid Mate-rial Fire Limits in Gaseous Oxidants2G 127 Guide for the Selection of Cleaning Agents forOxygen Systems2G 128 Guide for Control of Hazards and Risks in OxygenEnriched Systems2G 131 Practice for Cleaning of Materials and Componentsby Ultras
9、onic Techniques2G 136 Practice for Determination of Soluble Residual Con-taminants in Materials by Ultrasonic Extraction2G 144 Test Method for Determination of Residual Contami-nation of Materials and Components by Total CarbonAnalysis Using a High Temperature Combustion Ana-lyzer2G 145 Guide for St
10、udying Fire Incidents in Oxygen Sys-tems23. Terminology3.1 Definitions:autoignition temperature (AIT), nthe lowest temperatureat which a material will spontaneously ignite in an oxygen-enriched atmosphere under specific test conditions.G63, G72, G94, G 128contaminant, nunwanted molecular or particul
11、ate matterthat could adversely affect or degrade the operation, life, orreliability of the systems or components upon which itresides. G93, G 120, G 121, G 131, G 136, G 144contaminate, vto make unfit for use, either intentionally orunintentionally, by introduction of a contaminant. G 131,G 136conta
12、mination, n(1) the amount of unwanted molecular orparticulate matter in a system; (2) the process or condition ofbeing contaminated.1This terminology is under the jurisdiction of ASTM Committee G04 onCompatibility and Sensitivity of Materials in Oxygen Enriched Atmospheres and isthe direct responsib
13、ility of Subcommittee G04.03 on Terminology.Current edition approved March 10, 2000. Published June 2000. Originallypublished as G 126 94. Last previous edition G 126 94.2Annual Book of ASTM Standards, Vol 14.04.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA
14、 19428-2959, United States.DISCUSSIONContamination and cleanliness are opposing properties:increasing cleanliness implies decreasing contamination.G93, G 120, G 121, G 131, G 136, G 144control coupon (also witness coupon), n(1) a coupon madefrom the same material and prepared in exactly the same way
15、as the test coupons which is used to verify the validity of themethod or part thereof (G 120, G 131); (2) a coupon madefrom the same material as the test coupons but in this testmethod is not coated with the contaminant (G 121).DISCUSSION(1) in this practice, the control coupon is contaminatedin the
16、 same manner as the test coupons and is subjected to the identicalextraction procedure (G 120); (2) in this practice, the control coupon iscontaminated in the same manner as the test coupons and is subjectedto the identical cleaning procedure (G 131).degas, vthe process of removing gases from a liqu
17、id.G 131, G 136direct oxygen service, nservice in contact with oxygen-enriched atmosphere during normal operations. G63,G88, G94DISCUSSIONExamples are oxygen compressor piston rings or con-trol valve seats.impact-ignition resistance, nthe resistance of a material toignition when struck by an object
18、in an oxygen-enrichedatmosphere under a specific test procedure.G63, G94, G 128indirect oxygen service, nservice in which oxygen is notnormally but may be contacted as a result of an operatorerror, or process disturbance, such as liquid oxygen tankinsulation or liquid oxygen pump motor bearings. G63
19、,G88, G94DISCUSSIONExamples include, liquid oxygen tank insulation orliquid oxgen pump motor bearings.maximum use pressure, nthe greatest pressure to which amaterial can be subjected as a result of a reasonablyforeseeable malfunction, operator error or process distur-bance. G63, G94maximum use tempe
20、rature, nthe greatest temperature towhich a material can be subjected as a result of a reasonablyforeseeable malfunction, operator error, or process distur-bance. G63, G94molecular contaminant, nnonparticulate contaminant thatmay exist in either a gaseous, liquid, or solid state.DISCUSSIONMolecular
21、contaminant may be uniformly or nonuni-formly distributed as a solution or an emulsion or may be in the formof droplets. Molecular contaminants account for most of what consti-tutes nonvolatile residue. G 120, G 121, G 136, G 144nonmetal, nany material other than a metal, nonpolymericalloy, or any c
22、omposite in which the metallic component isnot the most easily ignited component and for which theindividual constituents cannot be evaluated independently,including (ceramics, such as glass, synthetic polymers, suchas most rubbers, thermoplastics, and thermosets, and naturalpolymers, such as natura
23、lly occurring rubber, wood, andcloth.) Nonmetallic is the adjective form of this term.G63, G93, G94, G 128nonvolatile residue (NVR), nmolecular or particulate mat-ter remaining following the filtration and controlled evapo-ration of a liquid containing contaminants.G 120, G 121, G 131, G 136, G 144o
24、perating pressure, nthe pressure expected under normaloperating conditions. G63, G94operating temperature, nthe temperature expected undernormal operating conditions. G63, G94oxygen compatibility (also oxidant compatibility), ntheability of a substance to coexist with both oxygen and apotential sour
25、ce(s) of ignition at an expected pressure andtemperature with a magnitude of risk acceptable to the user.G93, G 125, G 128, G 145oxygen-enriched, adjcontaining more than 25 mole percentoxygen. G63, G88, G94, G 128, G 145DISCUSSIONOther standards such as those publiched by NFPA andOSHA differ from th
26、e definition in their specification of oxygenconcentration.particle (particulate contaminant), na piece of matter in asolid state with observable length, width, and thickness.DISCUSSIONThe size of a particle is usually defined by its greatestdimension and is specified in micrometers.G 120, G 121, G
27、131, G 136, G 144qualified technical personnel, npersons such as engineersand chemists who, by virtue of education, training, orexperience, know how to apply physical and chemicalprinciples involved in the reactions between oxidants andother materials. G63, G88, G94, G 128, G 145reaction effect, nth
28、e personnel injury, facility damage,product loss, downtime, or mission loss that could occur asthe result of an oxygen fire. G63, G94surface roughness, Ra, nthe arithmetic average deviation ofthe surface profile from the centerline, normally reported inmicrometers. G 121, G 1223.2 Definitions of Ter
29、ms Specific to This Standard:aging, nthe exposure of a material to individual or combinedstresses such as time, temperature, pressure, abrasion, ion-izing radiation, light, impact with gas or particles, tensile orcompressive force (either static or cyclic), contact with othermaterials or chemicals,
30、or any other feature that may bepresent during a materials service life. G114artificial aging, naging in which a stress variable isoutside the domain of exposure that a material might see ina component for oxygen service or in which an alternativemechanism is used to produce an effect that simulates
31、 theresults of natural aging.DISCUSSIONThe degree of artificiality may vary on a large scale. Anexample of mild artificiality is exposure of a material to a greaterpressure than it experiences in the use condition. An example ofextreme artificiality is the use of sandpaper to increase a materialssur
32、face 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 be difficult to relate theresults to the use condition. Artificial aging that accelerates naturalaging but does not
33、alter the resulting effect is preferred. G114natural aging, naging in which a material is exposed toG126002conditions replicating those that are present in actual servicein a component for oxygen service. G114average regression rate (apparent burn rate), nthe averagerate at which the burning/solid-m
34、etal interface advancesalong the test sample length. G 124blank, nthe contamination level, sometimes referred to asthe background level, of a fluid when the test coupon isomitted. G 121cleanliness, nthe degree to which an oxygen system is freeof contaminant.DISCUSSIONCleanliness and contamination ar
35、e opposing properties:increasing cleanliness implies decreasing contamination. G93cleaning effectiveness factor (CEF), nthe fraction of con-taminant removed from an initially contaminated test cou-pon as determined by gravimetric techniques. G 122direct incident cause, nthe mechanical or thermodynam
36、icevent, such as breakage of a component or near-adiabaticcompression, the physicochemical property, such 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 an incident (see incident).G 145fibers,
37、 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 sustained combustion of a material under a combi-nation of specified conditions and at least one variableparameter. G 125DISCU
38、SSIONExamples are; oxidant concentration, diluent nature,pressure, temperature, geometry, and flow.fractional evaporation, nthe continuous evaporation of thequantity of liquid that results in a progressive increase in theconcentration of a less-volatile constituent(s) in the remain-ing liquid. G 145
39、hazard, nsource of danger; something that could harmpersons or property.DISCUSSIONThe magnitude of a hazard relates to the severity of theharm it could cause. G 128igniter, na material such as a small diameter wire that canburn under an electrical influence and is used to ignite thepromoter. G 124ig
40、nition temperature, nthe temperature at which a materialwill ignite an oxidant under specific test conditions. G 128incident, nan ignition or fire, or both, that is both undesiredand unanticipated, or an undesired and unanticipated conse-quence of an ignition or fire that was anticipated. G 145oxida
41、nt 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 parameteracceptable to the user. G 125oxidant index, nthe minimum concentration of an oxidant,such as oxygen, nitrous oxide, or fluo
42、rine, expressed as avolume percent, in a mixture of the oxidant with a diluent,such as nitrogen, helium, or carbon dioxide, that will justsupport sustained combustion of a material initially at givenconditions of temperature, pressure, flow conditions, andpropagation direction (see oxygen index).DIS
43、CUSSIONThe oxidant index (or limit) may be more specificallyidentified by naming the oxidant, such as oxygen index (or limit),nitrous oxide index (or limit), or fluorine index (or limit). Unlessspecified otherwise, the typical oxidant is oxygen, the typical diluent isnitrogen, and the typical temper
44、ature is ambient. G 125oxygen index, nthe minimum concentration of oxygen,expressed as a volume percent, in a mixture of oxygen andnitrogen that will just support sustained combustion of amaterial initially at room temperature under the conditionsof Test Method D 2863 (see Test Method D 2863). G 125
45、particulate, na general term used to describe a finelydivided solid of organic or inorganic matter. G93pressure limit, nthe minimum pressure of an oxidant (oroxidant mixture) that will just support sustained combustionof a material initially at given conditions of oxidant concen-tration, temperature
46、, flow condition, and propagation direc-tion.DISCUSSIONThe pressure limit may be more specifically identifiedby naming the oxidant: oxygen pressure limit, nitrous oxide pressurelimit, or fluorine pressure limit. G 125promoter, na material that provides thermal energy which isused to increase the tem
47、perature to start combustion of thematerial being tested. G 124residual contamination, Rc, nthe absolute mass of contami-nant remaining after a cleaning process, expressed in milli-grams per square centimeter of area or optionally as milli-grams per square metre. G 122risk, nprobability of loss or i
48、njury from a hazard.DISCUSSIONThe magnitude of a risk relates to how likely a hazardis to cause harm. G 128self-sustained combustion, ncombustion that consumes asample to the point at which the sample holder affects furthercombustion, assuming sufficient oxidizer. G 124temperature limit, nthe minimu
49、m temperature of an oxi-dant (or oxidant mixture) that will just support sustainedcombustion of a material initially at given conditions ofoxidant concentration, temperature, pressure, flow condition,and propagation direction.DISCUSSIONThe temperature limit may be more specifically identi-fied by naming the oxidant: oxygen temperature limit, nitrous oxidetemperature limit, or fluorine temperature limit. G 125threshold pressure, nthe minimum gas pressure (at aspecified oxygen concentration and ambient temperature)that su
