1、Designation: G74 08G74 13Standard Test Method forIgnition Sensitivity of Materials to Nonmetallic Materials andComponents by Gaseous Fluid Impact1This standard is issued under the fixed designation G74; the number immediately following the designation indicates the year of originaladoption or, in th
2、e case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method describes a techniquemethod to determine the relative sensitivity of mate
3、rials nonmetallic materials(including plastics, elastomers, coatings, etc.) and components (including valves, regulators flexible hoses, etc.) to dynamicpressure impacts by gases such as oxygen, air, or blends of gases containing oxygen.1.2 This test method describes the test apparatus and test proc
4、edures that may be employed in the evaluation of materials andcomponents for use in gases under dynamic pressure operating conditions up to gagegauge pressures of 10 000 psi (69 MPa) atambient temperature.69 MPa and at elevated temperatures.1.3 This test method is primarily a test method for ranking
5、 of materials. This materials and qualifying components for use ingaseous oxygen. The material test method is not necessarily valid for determination of the sensitivity of the materials in an“as-used” configuration since the material sensitivity maycan be altered because of changes in material confi
6、guration, usage, andenvironment. Acceptability of any material may be based on its performance at a particular test pressure, or test pressure may bevaried to determine the reactionservice conditions/interactions. However, the component testing method outlined herein can bevalid for determination of
7、 the sensitivity of components under service conditions.The current provisions of this method were basedon the testing of components having an inlet diameter (ID bore) less than or equal to 14 mm (see Note 1threshold of a material,as specified by the user.).1.4 A5 mm Gaseous Fluid Impact Sensitivity
8、 (GFIS) test system and a 14 mm GFIS test system are described in this standard.The 5 mm GFIS system is utilized for materials and components that are directly attached to a high-pressure source and haveminimal volume between the material/component and the pressure source. The 14 mm GFIS system is u
9、tilized for materials andcomponents that are attached to a high pressure source through a manifold or other higher volume or larger sized connection. Othersizes than these may be utilized but no attempt has been made to characterize the thermal profiles of other volumes and geometries(see Note 1).NO
10、TE 1The energy delivered by this test method is dependent on the gas volume being rapidly compressed at the inlet to the test specimen or testarticle. Therefore the geometry of the upstream volume (diameter and length) is crucial to the test and crucial to the application of the results to actualser
11、vice conditions. It is therefore recommended that caution be exercised in applying the results of this testing to rapid pressurization of volumes largerthan those standardized by this test method. This energy delivered by this standard is based on the rapid compression of the volume in either a 5 mm
12、ID by 1000 mm long impact tube or a 14 mm ID by 750 mm long impact tube.These two upstream volumes are specified in this standard based on historicapplication within the industry.1.5 This test method can be utilized to provide batch-to-batch comparison screening of materials when the data is analyze
13、daccording to the methods described herein. Acceptability of any material by this test method may be based on its 50 % reactionpressure or its probability of ignition based on a logistic regression analysis of the data (described herein).1.6 Many ASTM, CGA, and ISO test standards require ignition te
14、sting of materials and components by gaseous fluid impact,also referred to as adiabatic compression testing. This test method provides the test system requirements consistent with therequirements of these other various standards. The pass/fail acceptance criteria may be provided within other standar
15、ds and usersshould refer to those standards. Pass/fail guidance is provided in this standard such as that noted in section 4.6. This test methodis designed to ensure that consistent gaseous fluid impact tests are conducted in different laboratories.1.7 The criteria used for the acceptance, retest, a
16、nd rejection rejection, or any combination thereof of materials and componentsfor any given application shall be determined by the user and are not fixed by this method. However, it is recommended that at1 This test method is under the jurisdiction of ASTM Committee G04 on Compatibility and Sensitiv
17、ity of Materials in Oxygen Enriched Atmospheres and is the directresponsibility of Subcommittee G04.01 on Test Methods.Current edition approved Sept. 1, 2008May 1, 2013. Published October 2008October 2013. Originally approved in 1982. Last previous edition approved in 20012008 asG74 01.G74 08. DOI:
18、10.1520/G0074-08.10.1520/G0074-13.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recom
19、mends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1a minimum the
20、95 % confidence interval be established for all test results since ignition by this method is inherently probabilisticand should be treated by appropriate statistical methods.1.8 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard
21、.1.9 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. For specific pr
22、ecautions see Section 7.2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD2463 Test Method for Drop Impact Resistance of Blow-Molded Thermoplastic ContainersD3182 Practice for RubberMaterials, Equipment, and Procedures for Mixing Standard Compounds and Pr
23、eparing StandardVulcanized SheetsD3183 Practice for RubberPreparation of Pieces for Test Purposes from ProductsD1193D4894 Specification for Reagent WaterPolytetrafluoroethylene (PTFE) Granular Molding and Ram Extrusion MaterialsG14 Test Method for Impact Resistance of Pipeline Coatings (Falling Weig
24、ht Test)G63 Guide for Evaluating Nonmetallic Materials for Oxygen ServiceG88 Guide for Designing Systems for Oxygen ServiceG93 Practice for Cleaning Methods and Cleanliness Levels for Material and Equipment Used in Oxygen-Enriched EnvironmentsG94 Guide for Evaluating Metals for Oxygen ServiceG128 Gu
25、ide for Control of Hazards and Risks in Oxygen Enriched SystemsG175 Test Method for Evaluating the Ignition Sensitivity and Fault Tolerance of Oxygen Regulators Used for Medical andEmergency ApplicationsMNL36MNL 36 Safe Use of Oxygen and Oxygen Systems: Guidelines for Oxygen System Design, Materials
26、 Selection,Operations, Storage, and Transportation2.2 Military Standards:3MIL-STD-1330D Standard Practice for precision Cleaning and Testing of Shipboard Oxygen, Helium, Helium-Oxygen,Nitrogen, and Hydrogen SystemsMIL-STD-1622 Cleaning Shipboard Compressed Air SystemsMIL-D-16791-EMIL-D-16791G Deterg
27、ent,Detergents, General Purpose (Liquid, Nonionic) (26 Jan 1990)MIL-O-27210E Amendment 1-Oxygen,1Oxygen, Aviators Breathing, Liquid and Gas2.3 CGA Standards:4CGA V-9 Compressed Gas Association Standard for Compressed Gas Cylinder Valves2.4 ISO Standards:5ISO 291 PlasticsStandard Atmospheres for Cond
28、itioning and TestingISO 10297 Transportable gas cylindersCylinder valvesSpecification and type testingISO 10524-1 Pressure regulators for use with medical gasesPart 1: Pressure regulators and pressure regulators withflow-metering devicesISO 10524-2 Pressure regulators for use with medical gasesPart
29、2: Manifold and line pressure regulatorsISO 10524-3 Pressure regulators for use with medical gasesPart 3: Pressure regulators integrated with cylinder valvesISO 14113 Gas welding equipmentRubber and plastics hose and hose assemblies for use with industrial gases up to 450 bar(45 MPa)ISO 15001 Anesth
30、etic and Respiratory EquipmentCompatibility with OxygenISO 23529 RubberGeneral procedures for preparing and conditioning test pieces for physical test methods reference2.5 IEST Standards:6IEST-STD-CC1246D “Product Cleanliness Levels and Contamination Control Program,” Clean Rooms, August 20052 For r
31、eferencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from ASTM International, 100 Barr Harbor Drive, West Con
32、shohocken, PA 19428.3 Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/dodssp.daps.dla.mil.4 Available from Compressed Gas Association (CGA), 4221 Walney Rd., 5th Floor, Chantilly, VA 20151-2923, http:/.Equipment Li
33、st:5 Available from International Organization for Standardization (ISO), 1, ch. de la Voie-Creuse, CP 56, CH-1211 Geneva 20, Switzerland, http:/www.iso.org.L High-pressure Dwg 4-2219 (or equal)6 Available from Institute of Environmental Sciences and Technology (IEST), Arlington Place One, 2340 S. A
34、rlington Heights Rd., Suite 100, Arlington Heights, IL60005-4516, http:/www.iest.org.G74 1323. Summary of Method3.1 The gaseous impact test system is designed to expose exposes material specimens or small components/elements tohigh-velocity (dynamic) gaseous impact environments. The basic configurat
35、ion consists of a high-pressure accumulator, ahigh-speed pressurization (impact) valve, test system pressurization lines, test chamber/fixture, reaction chamber/fixture (formaterials tests), test chamber purge and vent systems, and a valve sequencer/control device. device for automatic control. Fig.
36、 1isdepicts a schematic of a typical 5 mm and 14 mm GFIS test system. Fig. 2a and b depict schematics of the typical reactionchambers used for material screening for this testing. Once a material test sample is installed in the reaction chamber, the assemblyis attached to the test article interface.
37、 Components to be qualified are attached directly to the test article interface.3.2 The general test procedure is to prepare the test specimen, material or component, record significant pretest data, pressurizethe system accumulators to the test pressure, calibrate the pressure rise time, and place
38、the test specimen in the test chamber. Thetest specimen material in the reaction chamber or install the component on the system interface. The test material or componentis then subjected to sequential gaseous impacts by alternately opening and closing the test chamber pressurization (impact) andvent
39、 valves. The test data obtained mayshall include test chamber pressures and temperatures, test chamber pressure rise times,pressurization and vent valve actuation times, and test gas temperature and pressure, and cycle-to-cycle sequence times. The testspecimen material or component is then removed a
40、nd examined for any significant changes andor evidence of reactions. Pertinentdata are recorded. The test is repeated using a fresh specimen for each impact test cycle until the desired user-selected criteria aremet.documentation is recorded.4. Significance and Use4.1 This test evaluates standard de
41、scribes how to evaluate the relative sensitivity of materials and components to dynamicpressure impacts by various gaseous fluid media (may include mixtures of gases).(can include gas mixtures).4.2 Any change Changes or variations in test specimen configurations, thickness, preparation, and cleanlin
42、ess maycan cause asignificant change in their impact sensitivity/reaction.ignition sensitivity/reaction. For material tests, the test specimenconfiguration shall be specified on the test report.4.3 Changes or variation in the test system configuration from that specified herein may cause a significa
43、nt change in theseverity produced by a dynamic pressure surge of the gaseous media.4.4 Areaction is indicated by an abrupt increase in test specimen temperature or temperature, by obvious changes in odor, color,or material appearance, or a combination thereof, as observed during post test post-test
44、examinations. Odor alone is not consideredpositive evidence that a reaction has occurred. When an increase in test specimen temperature is observed, a test specimen reactionmust be confirmed by visual inspection. To aid with visual inspection, magnification less than 10 can be used.4.5 Suggested cri
45、teria for test completion at a given pressure are:When testing components, the test article must be disassembledand the nonmetallic materials examined for evidence of ignition after completion of the specified pressure surge cycles.4.4.1 Each specimen is subjected to five impacts.4.4.2 A material pa
46、sses if no reactions occur in 20 successive samples.4.4.3 A material fails if one reaction occurs in a maximum of 20 or fewer successive samples.4.6 Ignition or precursors to ignition for any test sample shall be considered a failure and are indicated by burning, material loss,scorching, or melting
47、of a test material detected through direct visual means. Ignition is often indicated by consumption of thenon-metallic material under test, whether as an individual material or within a component. Partial ignition can also occur, as shownin Fig. 3a, b, and c, and shall also be considered an ignition
48、 (failure) for the purpose of this test standard.NOTE 2Arepresentative (exemplar) material or component may be requested by the test laboratory personnel for visual comparison with the post-testcondition of the test samples.4.7 Materials may be ranked by the maximum pressure (pressure threshold) at
49、which they pass For material testing, theprescribed procedure is conducted on multiple samples until a statistically significant number of ignitions or no-ignitions, or both,are achieved at various test pressures. The data is then analyzed by a procedure that calculates the median failure pressure (i.e.,the 50 % reaction pressure) or the functional form of the ignition probability versus pressure by logistic regression analysis.Materials tested in a similar configuration can be ranked against each other by either of these two criteria. The initi
