1、Designation: G 175 03Standard Test Method forEvaluating the Ignition Sensitivity and Fault Tolerance ofOxygen Regulators Used for Medical and EmergencyApplications1This standard is issued under the fixed designation G 175; the number immediately following the designation indicates the year oforigina
2、l adoption or, in the case of revision, 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 standard describes a test method for evaluating theignition
3、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 medical or emer
4、gency 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-indexadapters (CGA V
5、-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) having a low c
6、onse-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 applications (G 128)
7、.NOTE 1It is essential that a risk assessment be carried out onbreathing gas systems, especially concerning oxygen compatibility (referto ASTM G 63 and G 94) and toxic product formation due to ignition ordecomposition of nonmetallic materials as weighed against the risk offlammability (refer to ISO
8、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 active inoxygen syst
9、ems.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 contamination or its consequ
10、ences(G 88).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 limitations prior to use.2.
11、Referenced Documents2.1 ASTM Standards:G 63 Guide for Evaluating Nonmetallic Materials for Oxy-gen Service2G 88 Guide for Designing Systems for Oxygen Service2G 93 Practice for Cleaning Methods and Cleanliness Levelsfor Material and Equipment Used in Oxygen-EnrichedEnvironments2G 94 Guide for Evalua
12、ting Metals for Oxygen Service2G 128 Guide for Control of Hazards and Risks in OxygenEnriched Systems22.2 ASTM Adjuncts:Manual 36, Safe Use of Oxygen and Oxygen Systems32.3 Compressed Gas Association (CGA) Standards:CGA E-4, Standard for Gas Pressure Regulators4CGA G-4, Oxygen4CGA G-4.1, Cleaning Eq
13、uipment for Oxygen Service4CGA V-1, American National/Compressed Gas AssociationStandard for Compressed Gas Cylinder Valve Outlet andInlet Connections42.4 United States Pharmacopeial Convention Standard:1This test method is under the jurisdiction of ASTM Committee G04 onCompatibility and Sensitivity
14、 of Materials in Oxygen Enriched Atmospheres and isthe direct responsibility of Subcommittee G04.01 on Test Methods.Current edition approved April 10, 2003. Published May 2003. Originallypublished as PS 127 00. Last previous edition PS 127 00.2Annual Book of ASTM Standards, Vol 14.04.3Available from
15、 American Society for Testing and Materials, 100 Barr HarborDr., West Conshohocken, PA 194282959.4Available from Compressed Gas Association (CGA), 1725 Jefferson DavisHwy., Suite 1004, Arlington, VA 22202-4102.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 1
16、9428-2959, United States.USP 24 NF 19, Oxygen monograph52.5 Federal Regulation:21 CFR 868.2700 (a), Pressure regulator62.6 ISO Standards:ISO 10524 Pressure regulators and pressure regulators withflow-metering devices for medical gas systems7ISO 15001 Anaesthetic and respiratory equipment Com-patibil
17、ity with oxygen73. 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
18、 of the 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 theregulat
19、or to 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 s
20、hock 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
21、 applications.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 c
22、riteria for an acceptable test are specified in ISO10524, 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 regul
23、ator 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 p
24、arts 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 t
25、hroughnormal vent paths, with sparks that look similar to those frommetal applied to a grinding wheel, is acceptable.5. 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 sy
26、stem that complies with ISO 10524.5Available from U.S. Pharmacopeia (USP), 12601 Twinbrook Pkwy., Rockville,MD 20852.6Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401.7Available from International Organization for
27、 Standardization (ISO), 1 rue deVaremb, Case postale 56, CH-1211, Geneva 20, Switzerland.FIG. 1 Typical Test System ConfigurationG1750325.3 The ambient temperature surrounding the regulator mustbe 70 6 9F(216 5 C) for both phases of this test. For Phase2 testing, the test gas temperature can range f
28、rom 50 to 140 F(10 to 60 C).6. Materials6.1 For both phases of testing, the regulator must befunctional and in its normal delivery condition 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 nonpro
29、duction unit is used to qualify thedesign, it must be manufactured using design tolerances,materials, and processes consistent with a production 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 rea
30、ssembled and used for Phase 2.6.2 Ignition Pill Manufacture and AssemblyFollow thesesteps to manufacture and assemble the ignition pill 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
31、ignition pill was developed to simulate both particleimpact events and cylinder valve seat ignition. Particle impact events aresimulated by iron/aluminum powder within the ignition pill. Nonmetallicpromoters within the ignition pill simulate cylinder valve seat ignition.The nonmetallic promoters are
32、 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 in. 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 th
33、e 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 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
34、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 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 an
35、d 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 sealing 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
36、 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 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 m
37、old release and does notremain attached to the final pill. If the adhesive side faces the pill, it willadd an undesired residue to the 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
38、 bottom so as to melt thepolyamide sheet to the bottom of the cup.NOTE 8The soldering iron temperature should be approximately 450F (232 C).6.2.2.4 Remove the Kapton tape and the remaining polya-mide sheet.NOTE 9The polyamide sheet should easily tear away from the bottomof the cup, leaving a disc of
39、 polyamide sealed to the bottom of the cup. Ifit does not, the ignition pill has not been sealed properly, and theprocedure should be repeated.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 1mgi
40、ron 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 spatula 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 paint
41、brush can be used for this purpose. This is acritical step in making the pill, and it is important to ensure that nomaterial remains on the 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 s
42、o 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 sealing 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
43、 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.NOTE 13The copper seal tip temperature should be approximately450 F (232 C).6.2.4.4 Hold the soldering iron perpendicular to the top ofthe cup, rotate the soldering
44、iron slightly, and apply heat untilthe polyamide sheet is sealed to the top of the cup (Fig. 8). Letthe cup cool for 1 min before removing the remainingpolyamide 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
45、 properly, a disc of the polyamide sheetTABLE 1 Ignition Pill Materials and CharacteristicsMaterials for Phase 2Ignition PillPossibleSourceTotal RequiredEnergyNylon 6/6 rod stock Cylinder valve seatPolyamide sheet (2 mil) Cylinder valve stem lubricantAluminum powder (325 mesh) Contaminant from bottl
46、e 500 6 50 calIron powder (325 mesh) Contaminant from bottleG175033will 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 andren
47、der the pill unusable.FIG. 2 Brass Sealing FixtureFIG. 3 Nylon Rod in Sealing FixtureG1750346.2.4.5 Once the pill is properly 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 tha
48、t the pill is properly squared in thefixture so that it can be properly sanded. If the pill is not squared in thesealing fixture, 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
49、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 made according tothe drawings shown in Figs. 12 and 13.6.4 For Phase 1 testing, the minimum oxygen concentrationshall be of 99.5 % purity and shall not contain more than 10ppm hydrocarbons. For Phase
