Document 6bJ7BGYyVrao55noEKEZKGx01

Uf o IT AIR DISTRIBUTION SYSTEM ENGINEERING STANDARD FOR AIR MASKS AND CHEMICAL AIR SUITS SSuED THIS PAGE REVISED STANDARD REAFP'RMED mXrCH 1959 | FEB 1982 1 FEB 1982 S1 H Pag 1 of 4 This standard includes requirements cf the Occupational Safety and Health Act of 1970 (OSHA) as published in the Federal Register OSHA information is printed in red. j 1. SCOPE This standard describes safe facilities for supplying breathing-quality air from a plant air supply, portable compressor, or cylinders to air masks and chemical airsuit stations. For selection of proper respiratory equip ment, see S2H. 2. SAFETY 2.1 Carefully check the entire plant air supply system to make sure there is no possibility of cross contamination from toxic process vapors, inert gas. or radioactive materials which will not be removed by the usual air-line filters. Where such conditions are possible, a separate breathing-quality air supply should be provided. 2.2 Instrument air which has been dried is satisfactory for air mask use if it meets the requirements of 2.1 and the CO content does not exceed the limits as outlined in 2.2.1. Devices using instrument air should be checked to ensure that component failure cannot result in backflow of toxic vapors or inert gas into the air system. of 2.2.1. Installation of a compressed air purifier I see Note 3) should J be considered. 2.6 Air-distribution systems supplied by internallylubricated compressors should be checked periodically for condensed hydrjjcarbon content per CGA Specification G7.1. One such method is to pass a sample of the air to be tested through an adequate filter (0.8 gm MCEF) and measuring the increase in weight of the filter. Condensed hydrocarbons should not exceed 5 mg/m3 (S2H). 2.7 The additional hazard of undesirable or toxic con taminants being ^introduced from the use of portable com pressors must be recognized and guarded against. If possible, an electric motor-driven compressor shoul^be used. If this is hot practical, diesel engine-powered com pressors have less serious exhaust-recycle problems than those equipped ijdth gasoline engines. In either case, they should be provided with extensions to separate exhaust stacks, crank case vents, and compressor intakes; checked carefully for exhaust manifold leakage; and properlyoriented with regard to wind direction. 2.2.1 Breathing air shall meet at least the requirements for Grade D breathing air. as described in Compressed Gas Association Specification G-7.1 (maximum carbon monoxide content for Grade D is 20 ppm). See 6.1 of S2H. 2.3 Pure oxygen or oxygen-enriched air must never be used with air-line respirators. 2.4 Air-line couplings shall be incompatible with outlets for other gas systems to prevent inadvertent servicing of air-line respirators with nonrespirable gases or oxygen. 2.5 Nonlubricated compressors are preferred since oil is not introduced into the air supply as a potential source of carbon monoxide. If an internally lubricated compressor is used, it should be well maintained and must be operated well below the degradation temperature of the lubricant. To safeguard against the hazard of carbon monoxide being in the compressed air. the compressor shall be equipped with a high-temperature or carbon monoxide alarm, or both. If only a high-temperature alarm is used, the air from the compressor shall be tested frequently for carbon monoxide, to ensure it meets the requirements 2.8 Purchased jcylinders of breathing air should be analyzed before use, preferably by the plant. See S2H for requirements and specifications. 2.9 State and local requirements shall be examined as they may be more restrictive. ii 2.10 Air-distribution systems utilize air filters or filter/regulators (or both). They must not be used where system pressure jor temperature may exceed maximum rated operating conditions. 2.10.1 Polycarbonate plastic bowls are normally supplied on filters and filter/regulators. They can be damaged and possibly burst if exposed to such substances as certain solvents, strong alkalies, compressor oils con taining ester-based additives, or synthetic oils. Fumes of these substances ^in contact with the polycarbonate bowl, externally or internally, can also result in damage. Polycarbonate bowls used in such environments, should be equipped with metal guards. j 2.10.1.1 jVletal bowls are acceptable alternates to installing guards.: Portions printed in red are from OSHA regulations. Section 1910.134 Vendors and merchandise designations are given to describe materials and may not include all acceptable products. Substitutions by suppliers are to be made only on approval of the local authority initiating the use of this standard. SUBCOMMITTEE NO 28 DU 009134 DUP 0805740 S1 H Page 2 AIR DISTRIBUTION SYSTEM FOR AIR MASKS AND CHEMICAL AIR SUITS This Page Rev Nov 1983 2.10.2 If outlet pressures in excess of the filter/regulator pressure setting could cause downstream equipment to rupture or malfunction, install a pressurerelief device downstream of the filter/regulator. The relief pressure and flow capacity of the relief device must satisfy system requirements. 2.11 Where the possibility of damage to a plastic filter bowl or filter/regulator bowl exists due to location in an area where it can easily be struck, the bowl must be guarded with a metal bowl guard. Refer to Figures 1 and 2, Notes 2 and 6. 3. INSTALLATION 3.1 Two installations are available. Figure 1 shows the arrangement to be used with demand-type air masks. Pressure should be 50 to 150 psi and air flow 1V2 stan dard cfm per mask. Figure 2 shows the arrangement for constant-flow type air masks and chemical air suits. Pressure must be below j 50 psi. Air flow required is 4 standard cfm for a tight-fitting air mask. 6 cfm for a loose-fitting mask, and 15, to 30 cfm for a chemical air suit. ! j 3.2 The following piping specifications are suggested for the steel portions of Figures 1 and 2: -i a. Galvanized system - SP109U b. Not galvanized j - SP108U i Pipe shall be cleaned to remove dirt, rust, and oil, see SP4M. i' 202 DUP 0805741 mm DU 009135 Tu s Page Rev Feb 1982 To additional outlets External relief valve required AIR DISTRIBUTION SYSTEM F-OR AIR MASKS AND CHEMICAL AlRj SUITS S'H Page 3 /2 brass pipe or copper tubing, see Note 8 Breathing air cylinder with regulator i Figure 1A -- With Air Cylinder Supply. quick-disconnecr couplings with auto matic shutoff, see Note 5 DUP 0805742 Figure IB -- With Plant Air Supply FIGURE 1 - TYPICAL INSTALLATIONS FOR DEMAND-TYPE AIR- MASK STATIONS ~or notes, see page 4 DU 009136 S1H Page 4 AIR DISTRIBUTION SYSTEM FOR AIR MASKS AND CHEMICAL AIR SUITS This Page Issued Feb 1982 Take-of* at top of header . See Note 1 A steel Steel neader (see Note 7i ----------------------------------- ------------------ $$-- Plug Slope end To additional Alters and outlets as required Vi" brass pipe or copper 1" globe tubing, see Note Air supply, steel TT 1 plugged connection 6' e for chemical air suit filter T Combination V4" valve iXnf teeZ Hrr + -DHrip DocKet at end of header /i" socket end connec tion, see Notes 4 and 5 \ To additional, outlets as L required, see Note 8 Air-mask station and pressure regulator, filter-regulator. Post sign at each station: reduce to required pressure, see Note 6 z ------Floor line see Notes 2. 3. and 6 AIR MASK Blow Out Line Before Using Mask FIGURE 2 - TYPICAL AIR-MASK STATION, CONSTANT-PLOW TYPE, PLANT AIR SUPPLY Notes 1. Care must be taken to avoid contamination of breathing air by process or instrument connections, 'see 2.1. Z Suggested air-line filters, C. A. Norgren Co. Littleton, CO 80120. Base configuration on intended use and location. Configuration Norgren Model No. Configuration Norgren Model No. Plastic bowl, no guard, manual drain F12-400-M3TA Metal bowl, manual drain F12-4Q0-M3MA Plastic bowl, slotted metal guard, manual drain F12-400-M3PA Metal bowl, .automatic dram F12-400-A3MA Plastic bowl, no guard, automatic dram Plastic bowl, slotted metal guard, automatic dram F12-400-A3TA F12-4O0-3Pa Metal bowl, manual dram. liquid level gage Metal bowl, automatic dram, liquid level gage F12-400-M3DA F12-400-A3DA Equivalents may be used Filter element should not exceed 50-micron size. Filter should be supported 'Itso that bowl can be detached a^o removed readily. Where air supply is of questionable quality, a compressed-air purifier such as the Oel-Monox. manufactured by Deitech Engineering, -re. Century Park. New Castle. DE 19720. is recommended in place of the standard air-line filter Note Predrying of air before it is passed tnroogh me Del-Monox purifier will prevent the color change of the cartridge and give a false indication of contamjnant removal efficiency If predned air is to be used, consult manufacturer for special instructions. Alternate is the use of a CO analyzer, such as Ecotyzer. manufactured by Energetics Science me, 6 Skyline Drive. Hawthorn. NY 10532. I p-ar* sr3M standardize these connections and limit them for this use only Suggested type: "Perfecting'* Socket No. 2AM2 tuse Plug No A2S2 on hose/, or equal Perfecting Div Duff Norton Co. Amstar Corp. 100 Pioneer Onve. Charlotte. NC 28232. Outlets are .assignee to be used wan ,J4 nch ID hose fittings for air masks. Three-quarter mch ID air hose for chemical air suits would require different part numoers Pipe and outlet assembly is to be separately supported to withstand the strain of frequent use. | Suggested filter/regulator, C. A. Norgren Co, Littleton. CO 80120. Base configuration on intended use and location. Configuration Norgren Model No. Transparent bowl, manual dram B12-621- M3LA1 Transparent bowl with guard, manual dram B12-618- M3LA| Transparent bowl, automatic dram 912-621- A3LA Transparent bowl with guard. . automatic dram 812-618 A3LA Metal bowl with sight glass, manual dram 812-697-M3LAI Metal bowl with sight glass. automatic dram B12-697-A3LA Regulator includes pressure relief and gage. Range 1 -50 psi. Filter specification similar to Note 2 Reguiai;or may be omitted i* air Suppit s within range of respirator to be used, or if respirator is equipped with regulating vaiva such as MSA !Hyper-F(o valve Recommended header size and take-offs: ; Header Size (In) No. Take-Off Line* per Heeder Max No. Air Masks per Take-Off Line 11 1 '/j 5 16 I 10 2 10 .10 | m corrosive atmospheres, stainless steel pipe or tubmg may be considered an acceptable alternate to (bras$ and copper Block valves are not indicated. They are to be provided as reauired by the user. i. ^onions pr.nted >n red are from OSHA regulations. Section 1910.134 D*U 009137 H> I 172 DUP 0805743