Chapter 19. Welding, Cutting and Brazing (Hot Work)

I. Welding equipment must be chosen for safe application to the work and must be installed properly.

II. Welders should be properly instructed to operate welding equipment.

III. Welders should wear proper personal protective equipment including heavy trousers, long sleeve shirt buttoned at the collar, leather gloves with gauntlets, and possibly a respirator.

IV. Mechanical ventilation should be provided when welding or cutting when there is:

A. less than 10,000 cubic feet of space per welder; and

B. less than 16 feet of overhead height.

V. Mechanical or local exhaust ventilation or the use of airline respirators should be provided when performing hot work with:

A. Zinc, lead, cadmium, mercury, or beryllium based or coated materials in enclosed spaces;

B. Stainless steel with inert-gas equipment;

C. In confined spaces; or

D. Where an unusual condition can cause an unsafe accumulation of contaminants.

VI. The unit supervisor should ensure that the paint is stripped back at lease 4 inches from the area of heat application, or provide workers with airline respirators.

VII. Proper shielding and eye protection should be provided to protect welders from visible and ultraviolet radiation, sparks, and flying debris.

VIII. When work permits, booth or other non-combustible screening with a low reflective finish should be provided to reduce exposure of the welder to visible and ultraviolet light.

IX. Proper fire prevention methods should be taken in welding or other hot work areas.

A. Isolate welding and cutting.

B. Remove fire hazards from the area. No welding, cutting, or heating should be done in the presence of flammable paints, solvents, or heavy dust concentrations.

C. Provide a fire watch.

D. Provide adequate fire extinguishers.

X. Gas welding and cutting.

A. Fuel and oxygen hose should be easily distinguishable (color-coded) and must not be interchangeable.

B. Hoses should be inspected prior to use and repaired or replaced if damaged.

C. Use only approved bronze or brass fittings. Copper fittings should never be used on acetylene cylinders.

D. Do not use oil, grease, or similar organic materials on any torch or regulator.

E. Never face a gauge while opening the cylinder valve.

F. Hoses should be purged prior to lighting the welding torch.

XI. Electric arc welding.

A. The welding machine must be thoroughly dry prior to use.

B. Coiled welding cable should be spread out, and the ground lead firmly attached to the work prior to welding.

C. Work and electrode lead cables should be frequently inspected and damaged insulation or exposed bare conductors should be replaced.

D. There should be no repairs or splices within 10 feet of the electrode holders except where splices insulation equals or exceeds the insulation of the cable.

E. Cables should not be coiled around the welder's body.

F. Arc welders should wear only clean gloves and clothing of fire-resistant materials with collars and long sleeves buttoned.

G. Electrodes should be removed and the holders protected to prevent electrical contact when the electrode holders are to be left unattended.

XII. Resistance welding.

A. All equipment must be installed by a qualified electrician.

B. A safety-type disconnect, i.e., switch, circuit breaker, or circuit interrupter, should be conveniently located at or near the machine for emergency shut off.

C. Ignition tubes must have thermal protection switches.

D. Appropriate guards should be in place to prevent accidental equipment activation.