Document vy2gorapBGXzrppNdaO7ZJ2jZ

Wednesday, December 28, 1960 FEDERAL REGISTER lj'Sld it and the pressure reducer. There shall equal to eight diameters of the cable, or g 50-204,139 Protection to oilier em be no means of cutting off or bypassing when the wires on the crown of the ployees. this safety valve. Inspection and ade quate maintenance of the vessel. Includ ing regular testing of the safety valve, are mandatory. 50-204.122 Unfired pressure vessels. (a) Air receivers shall be so Installed that all drains, handholes, and manholes therein are easily accessible. <b) Air receivers shall be supported with sufficient clearance to permit a com plete external Inspection and to avoid corrosion of external surfaces. (c) Under no circumstances shall air receivers be buried underground or lo cated in an Inaccessible place. (d) The receiver shall be located as dose to the compressor or aftercooler as Is possible to keep the discharge short. (e) The receiver shall be located In a cool place to facilitate the condensation of moisture and oil vapors. strand are worn down to less than 60 percent of their original diameter. (d) Crane hoist cable shall be lu bricated and Inspected at frequent Intervals. Ventilation and Protection in Welding and Cutting 50-204.135 Welding and culling in confined (paces. For the purpose of this section a con fined space shall mean: (a) A space of less than 10,000 cubic feet per welder, or (b> A space having an overhead height of less than 16 feet, or (c) A space In which there are struc tural barriers to the extent that they significantly obstruct cross ventilation. 50-204.136 Ventilation in confined spaces. In all cases employees In the Immedi ate vicinity of welding operations shall be protected In accordance with sections 50-204.269 and 50-204.298. 50-204.140 Inert-gas melal-arc weld ing. Since the inertcg&s metal-arc welding process involves the productlon'of ultra violet radiation of intensities five to thirty times that produced during shielded metal-arc welding, the decom position of chlorinated solvents by ultra violet rays, and the liberation of toxic fumes and gases, employees shall not be permitted to engage in, or be exposed to the process unless: (a) Hie use of chlorinated solvents Is kept at least 200 feet from the exposed arc; surfaces prepared with chlorinated solvents are thoroughly dry before welding Is permitted on such surface. Tools ami Equipment g 50-204.127 Maintenance. All welding and cutting operations car (b) Shaded goggles with side shields ried on fin confined spaces shall be ade are worn by helpers and others In the quately mechanically ventilated to pre area not protected from the arc by lgpch employer shall be responsible for the safe condition of the tools usedjty his employees, whether furnished by him or by them, and be sure that such tools p suited by safe design and construction for the work to be done. 50-204.128 Portable electric power loots. (a) Electric power tods showing worn, deteriorated or inadequate Insulation, split or chipped plugs, worn or bent plugs, terminals, defective switch, shall be repaired. (b) Portable electric power tools shall beeffectlvely grounded to maintain at all times an effective ground on the noncurrent carrying parts of the tools. g 50-204.129 Portable pneumatic tools. (a) The operating trigger on portable hand-operated pneumatic equipment shall be so located as to minimize the vent the accumulation of toxic gases or possible oxygen deficiency or &lr sup plied respirators approved by the U.S. Bureau of Mines shall he provided to the welder and all other personnel In the Immediate vicinity. 8 50-204.137 Mechanical ventilation. Mechanical ventilation shall consist of either general ventilation systems or lo cal exhaust systems. (a) General ventilation shall be at the minimum rate of 2,000 cubic feet per minute per welder. (b) Local exhaust shall consist of freely movable hoods Intended to be placed by the welder as near as prac ticable to the work being welded and pro vided with a rate of air flow sufficient to maintain a velocity In the direction of the hood of 100 linear feet per minute In the zone of welding when the hood Is at Its most remote distance from the point screening. (c) Protective clothing Is worn by welders and others within the area ex posed to radiation so that the skin Is covered completely to prevent burns and other damage by ultraviolet rays; shirts worn are dark In color to reduce reflec tion to the face from underneath the helmet; exposed cotton clothing Is cov ered since it disintegrates rapidly when exposed to high Intensities of ultraviolet rays; welding helmets and hand shields are free of leaks and openings, and free of highly reflective surfaces. <d) Local exhaust ventilation or suppUed air respirators are provided in all cases when doing inert-gas metal-arc welding of stainless steel to protect against dangerous concentrations of nitrogen dioxide. 8 50-204.141 General welding and cut ting. possibility of accidental operation and of welding. Welding and cutting not Involving shall be arranged to close the air Inlet valve automatically when the pressure of the operator's hand la removed. (b) A tool retainer shall be Installed g 50-204.138 Welding and culling in volving metals of toxic significance. (a) Welding and cutting Involving the conditions or materials described In sec tions 60-204.135 and 50-204.138 may normally be done without special pre cautions, but where, because of unusual on each piece of pneumatic equipment following metals whether or not in con physical or atmospheric conditions, a which, without such a retainer, may fined spaces or In other enclosed spaces harmful accumulation of contaminants eject the tooL shall be done In accordance with the pro would exist, mechanical ventilation or tc) No tool change or work other than visions of sections 204.130 and 204.137. suitable respiratory protective equipment regular operations shall be made or done (1) Zinc-bearing base of filler metals shall be provided. on any piece of portable hand-operated pneumatic equipment unless the stop or metals coated with zinc-bearing ma terials. Electrical Installation and Equipment valve In the air line supplying that equip (2) Lead base metals. 8 50--204.148 Electrical Installation and mentIs closed. (3) Cadmium-bearing filler materials. equipment. g 50-204.130 Cables, ropes, and chains. (a) Chains, ropes, cables, hooks, rings, slings, and other devices and accessories used for hoisting and lifting shall not be subjected to greater working loads than recommended by their manufacturers. They shall be frequently Inspected and shall be renewed when lnpectlon reveals unsafe conditions. (b) Bolts or na. shall not be used to connect, splice, or shorten chains. (b) Welding or cutting Involving the following metals' In confined spaces shall be dime using local exhaust ventilation or alr-Une respirators approved by the UJ5. Bureau of Mines. (1) Metals containing lead, other than as an impurity, or metals coated with lead-bearing materials, including paint. (2) Cadmium-bearing or cadmium- coated base metals. <3) Metals coated with mercury-bear ing metals, including paint. Electrical conductors and equipment Installed within or on buildings and other premises and the conductors that connect the installation to a supply of electricity and other outside conductors adjacent to the premises shall conform tothe minimum requirements of the Na tional Electrical Code, 1859 Edition, National Fire Protection Association. Mechanical Power Transmission Apparatus Knots shall not be tied In the chain. (c) A hoist cable shall be considered unsafe and shall be replaced wben upon Inspection 10 percent or more of the total number of wires are broken In a length (4) Beryllium-containing base or filler metals. Because of its high toxicity, work Involving beryllium shall be done with both local exhaust ventilation and alr-Une respirators. 6 50-204.153 Flywheels. Flywheels located so that any part Is 7 feet or less above floor or platform shall be guarded In one of the following ways;