1、Designation: G175 03 (Reapproved 2011)Standard Test Method forEvaluating the Ignition Sensitivity and Fault Tolerance ofOxygen Regulators Used for Medical and EmergencyApplications1This standard is issued under the fixed designation G175; the number immediately following the designation indicates th
2、e year oforiginal adoption or, in the case of revision, 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 standard describes a test method for evaluati
3、ng theignition sensitivity and fault tolerance of oxygen regulatorsused for medical and emergency applications.1.2 For the purpose of this standard, a pressure regulator isa device, also called a pressure-reducing valve, that is intendedfor medical or emergency purposes and that is used to converta
4、medical or emergency gas pressure from a high, variablepressure to a lower, more constant working pressure 21 CFR868.2700 (a).1.3 This standard applies only to oxygen regulators used formedical and emergency applications that are designed andfitted with CGA 540 inlet connections or CGA 870 pin-index
5、adapters (CGA V-1).1.4 This standard provides an evaluation tool for determin-ing the fault tolerance of oxygen regulators used for medicaland emergency applications. A fault tolerant regulator isdefined as (1) having a low probability of ignition as evaluatedby rapid pressurization testing, and (2)
6、 having a low conse-quence of ignition as evaluated by forced ignition testing.1.5 This standard is not a design standard; however, it canbe used to aid designers in designing and evaluating the safeperformance and fault tolerance capability of oxygen regula-tors used for medical and emergency appli
7、cations (GuideG128).NOTE 1It is essential that a risk assessment be carried out onbreathing gas systems, especially concerning oxygen compatibility (referto Guides G63 and G94) and toxic product formation due to ignition ordecomposition of nonmetallic materials as weighed against the risk offlammabi
8、lity (refer to ISO 15001.2). See Appendix X1 and X2.1 fordetails.1.6 This standard is also used to aid those responsible forpurchasing or using oxygen regulators used for medical andemergency applications in ensuring that selected regulators aretolerant of the ignition mechanisms that are normally a
9、ctive inoxygen systems.1.7 This standard does not purport to address the ignitionsensitivity and fault tolerance of an oxygen regulator caused bycontamination during field maintenance or use. Regulatordesigners and manufacturers should provide design safeguardsto minimize the potential for contamina
10、tion or its consequences(Guide G88).1.8 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 regulatory limi
11、tations prior to use.2. Referenced Documents2.1 ASTM Standards:2G63 Guide for Evaluating 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-EnrichedEnvironmentsG9
12、4 Guide for Evaluating Metals for Oxygen ServiceG128 Guide for Control of Hazards and Risks in OxygenEnriched Systems2.2 ASTM Manual:Manual 36 Safe Use of Oxygen and Oxygen Systems22.3 Compressed Gas Association (CGA) Standards:CGA E-4 Standard for Gas Pressure Regulators3CGA G-4 Oxygen31This test m
13、ethod is under the jurisdiction of ASTM Committee G04 onCompatibility and Sensitivity of Materials in Oxygen Enriched Atmospheres and isthe direct responsibility of Subcommittee G04.01 on Test Methods.Current edition approved April 1, 2011. Published April 2011. Originallypublished as PS 127 00. Las
14、t published as B175 03. DOI: 10.1520/G0175-03R11.2For 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 onthe ASTM website.1Copyright A
15、STM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.CGA G-4.1 Cleaning Equipment for Oxygen Service3CGA V-1 American National/Compressed Gas AssociationStandard for Compressed Gas Cylinder Valve Outlet andInlet Connections32.4 United States Pharmaco
16、peial Convention Standard:USP24NF19Oxygen monograph42.5 Federal Regulation:21 CFR 868.2700 (a) Pressure regulator52.6 ISO Standards:ISO 10524 Pressure regulators and pressure regulators withflow-metering devices for medical gas systems6ISO 15001 Anaesthetic and respiratory equipment Com-patibility w
17、ith oxygen63. Summary of Test Method3.1 This test method comprises two phases. A regulatormust pass both phases in order to be considered ignitionresistant and fault tolerant.3.2 Phase 1: Oxygen Pressure Shock TestIn this testphase, fault tolerance is evaluated by testing the ignitionresistance of t
18、he regulator design by subjecting the regulator toheat from oxygen pressure shocks. The test is performedaccording to ISO 10524, Section 11.8.1, which is similar toCGA E-4.3.3 Phase 2: Regulator Inlet Promoted Ignition TestInthis test phase, fault tolerance is evaluated by subjecting theregulator to
19、 the forced application of a positive ignition sourceat the regulator inlet to simulate cylinder valve seat ignitionand particle impact events. The ignition source is representa-tive of severe, but realistic, service conditions. The Phase 1component test system is used for Phase 2 to pressure shock
20、aregulator upstream of its inlet so that an ignition pill is kindledto initiate combustion within the regulator.4. Significance and Use4.1 This test method comprises two phases and is used toevaluate the ignition sensitivity and fault tolerance of oxygenregulators used for medical and emergency appl
21、ications.4.2 Phase 1: Oxygen Pressure Shock TestThe objective ofthis test phase is to determine whether the heat from oxygenpressure shocks will result in burnout or visible heat damage tothe internal parts of the regulator. Phase 1 is performedaccording to ISO 10524, Section 11.8.1.4.2.1 The criter
22、ia for an acceptable test are specified inISO 10524, Section 11.8.1.4.2.2 The pass/fail criteria for a regulator are specified inISO 10524, Section 11.8.1.4.3 Phase 2: Regulator Inlet Promoted Ignition TestTheobjective of this test phase is to determine if an ignition eventupstream of the regulator
23、inlet filter will result in sustainedcombustion and burnout of the regulator.4.3.1 The criterion for an acceptable test is either, (1) failureof the regulator, which is defined as the breach of thepressurized regulator component (burnout) and ejection ofmolten or burning metal or any internal parts
24、from theregulator, or (2) if the regulator does not fail, consumption ofat least 90 % of the ignition pill as determined by visualinspection or mass determination. Failure of the regulator at theseal ring does not constitute an acceptable test.4.3.2 Momentary (less than 1 s) ejection of flame throug
25、hnormal vent paths, with sparks that look similar to those frommetal applied to a grinding wheel, is acceptable.3Available from Compressed Gas Association (CGA), 4221 Walney Rd., 5thFloor, Chantilly, VA 20151-2923, http:/.4Available from U.S. Pharmacopeia (USP), 12601 Twinbrook Pkwy., Rockville,MD 2
26、0852.5Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.6Available from International Organization for Standardization (ISO), 1, ch. dela Voie-Creuse, Case postale 56, CH-1211, Geneva 20,
27、Switzerland, http:/www.iso.ch.FIG. 1 Typical Test System ConfigurationG175 03 (2011)25. Apparatus5.1 Both phases of this test will be performed in a testsystem as specified by ISO 10524.5.2 Fig. 1 depicts a schematic representation of a typicalpneumatic impact test system that complies with ISO 1052
28、4.5.3 The ambient temperature surrounding the regulator mustbe 70 6 9F (21 6 5C) for both phases of this test. For Phase2 testing, the test gas temperature can range from 50 to 140F(10 to 60C).6. Materials6.1 For both phases of testing, the regulator must befunctional and in its normal delivery cond
29、ition and must betested as supplied by the manufacturer. If a regulator issupplied with a filter, perform the test with the filter installed.If a prototype or nonproduction unit is used to qualify thedesign, it must be manufactured using design tolerances,materials, and processes consistent with a p
30、roduction unit. Apossible total of eight regulators will be tested; three in Phase1 and five in Phase 2. If the regulators from Phase 1 areundamaged, they may be reassembled and used for Phase 2.6.2 Ignition Pill Manufacture and AssemblyFollow thesesteps to manufacture and assemble the ignition pill
31、 used forPhase 2 testing. Use the materials listed in Table 1 tomanufacture the ignition pills. Total required energy for theignition pill is 500 6 50 cal.NOTE 2The ignition pill was developed to simulate both particleimpact events and cylinder valve seat ignition. Particle impact events aresimulate
32、d by iron/aluminum powder within the ignition pill. Nonmetallicpromoters within the ignition pill simulate cylinder valve seat ignition.The nonmetallic promoters are also used to bind and kindle ignition of themetallic powder.6.2.1 Forming the Cup:6.2.1.1 Turn the nylon rod down to 0.28 +0/-0.0025 i
33、n. OD(7.11 +0/-0.064 mm) OD.6.2.1.2 Place the rod in the brass sealing fixture (Fig. 2),sand the rod face flat, and remove any noticeable burrs.NOTE 3Fig. 3 shows the nylon rod held in the sealing fixture forsanding.6.2.1.3 Use a316 in. (4.76 mm) dia end mill to bore an 0.06in. (1.52 mm) deep cavity
34、 in the rod to form a cup.6.2.1.4 Cut the cup from the rod.NOTE 4The cup should be slightly taller than 0.13 in. (3.30 mm). Thisis an initial pill height; the final pill height is achieved after sanding andis based on the required final pill weight.6.2.1.5 Using a #69 drill, drill a hole completely
35、through thecenter of the bottom of the cup. If necessary, square the bottomof the cup with a file to ensure it sits flat and will not tip over.NOTE 5The pill base and dimensions are shown in Fig. 4.6.2.2 Sealing the Bottom of the Cup:6.2.2.1 Put the cup and nylon push tool (Fig. 5) into thebrass sea
36、ling fixture and adjust the push tool so that the top ofthe cup is just slightly below the surface of the sealing fixture.NOTE 6If the top of the cup is not situated in the sealing fixture justslightly below the surface, the heat of the soldering iron could deform thetop of the cup.6.2.2.2 Place one
37、 layer of polyamide sheet in the bottom ofthe cup and cover it with Kapton tape, with the adhesive sidefacing away from the pill.NOTE 7The Kapton tape is used as a mold release and does notremain attached to the final pill. If the adhesive side faces the pill, it willadd an undesired residue to the
38、pill.6.2.2.3 Seal the polyamide to the bottom of the cup using asoldering iron tip (Fig. 6). Ensure that heat is applied evenlyaround the perimeter of the inside cup bottom so as to melt thepolyamide sheet to the bottom of the cup.NOTE 8The soldering iron temperature should be approximately450F (232
39、C).6.2.2.4 Remove the Kapton tape and the remaining poly-amide sheet.NOTE 9The polyamide sheet should easily tear away from the bottomof the cup, leaving a disc of polyamide sealed to the bottom of the cup. Ifit does not, the ignition pill has not been sealed properly, and theprocedure should be rep
40、eated.6.2.3 Filling the Cup:6.2.3.1 Place the cup on a scale capable of a resolution to0.1 mg and zero the scale.6.2.3.2 Add 10 6 1 mg aluminum powder and 3 6 1mgiron powder to the cup. Put the aluminum powder in the cupfirst, then the iron.NOTE 10If too much iron is added to the pill, a magnetic sp
41、atula maybe used to remove iron from the cup.6.2.3.3 After filling the cup, push any metallic powder onthe top surface of the cup into the cup.NOTE 11A small paintbrush can be used for this purpose. This is acritical step in making the pill, and it is important to ensure that nomaterial remains on t
42、he surface to inhibit a proper heat seal.6.2.4 Sealing the Cup:6.2.4.1 Put the cup and the nylon push tool into the brasssealing fixture and adjust the push tool so that the top of the cupis just slightly below the surface of the sealing fixture.NOTE 12If the top of the cup is not situated in the se
43、aling fixture justslightly below the surface, the heat of the soldering iron could deform thetop of the cup.6.2.4.2 Place one layer of polyamide sheet over the top ofthe cup, then cover the polyamide sheet with Kapton tape.6.2.4.3 Place a copper seal tip (Fig. 7) onto the tip of thesoldering iron.NO
44、TE 13The copper seal tip temperature should be approximately450F (232C).6.2.4.4 Hold the soldering iron perpendicular to the top ofthe cup, rotate the soldering iron slightly, and apply heat untilthe polyamide sheet is sealed to the top of the cup (Fig. 8). LetTABLE 1 Ignition Pill Materials and Cha
45、racteristicsMaterials for Phase 2Ignition PillPossibleSourceTotal RequiredEnergyNylon 6/6 rod stock Cylinder valve seatPolyamide sheet (2 mil) Cylinder valve stem lubricantAluminum powder (325 mesh) Contaminant from bottle 500 6 50 calIron powder (325 mesh) Contaminant from bottleG175 03 (2011)3the
46、cup cool for 1 min before removing the remainingFIG. 2 Brass Sealing FixtureFIG. 3 Nylon Rod in Sealing FixtureG175 03 (2011)4polyamide sheet and Kapton tape. Repeat this process until thecup is capped with five layers of polyamide sheet (Fig. 9).NOTE 14If the cup is sealed properly, a disc of the p
47、olyamide sheetwill be sealed to it and the remainder of the sheet will easily pull off. It isespecially critical to ensure the first layer of polyamide sheet is completelysealed to the top of the cup, or else the pill contents will leak out andrender the pill unusable.6.2.4.5 Once the pill is proper
48、ly sealed and cooled, removeit from the brass sealing fixture. Place the pill upside down inthe sealing fixture so that the pill bottom is exposed.NOTE 15Take care to ensure that the pill is properly squared in thefixture so that it can be properly sanded. If the pill is not squared in thesealing fi
49、xture, the cup bottom can be sanded open, thus exposing themetallic powder and ruining the pill.6.2.4.6 Using a belt or palm sander, sand the pill until a finalweight of 67 6 1 mg is achieved. Use the push tool to removethe pill from the sealing fixture.6.3 Adapter Block and Pill Holder ManufactureAdapterblocks and pill holders for regulators with CGA 540 inletconnections shall be made according to the drawings shown inFigs. 10 and 11. Adapter blocks and pill holders for regulatorswith CGA 870 pin-index adapters shall be ma
