SECTION 23. WELDING, CUTTING, AND BRAZING

23.1 GENERAL

All gas welding operations at APO must be concerned with the possibilities of “flashbacks” or “regulator burnout's”, protection from intense lights, sparks causing fires, and potentially explosive combinations. The following procedures give basic guidelines to prevent such problems.

23.2 PROTECTIVE CLOTHING

Eye Protection: all persons in the immediate area of a welding operation will wear eye protection, such as goggles or shields. This protection is not only to protect against flying materials but also to reduce the intensity of light. A basic guide is shown below for selecting the proper glass shade for particular operations.

Shade No. listed to right of description:

Shielded metal-arc welding 1/16-, 3/32-,1/8-, 5/32-inch electrodes......... 10
Gas-shielded arc welding (nonferrous) 1/16-,3/32-, 1/8-, 5/32-inch electrodes.......... 11
Gas-shielded arc welding (ferrous) 1/16-, 3/32-,1/8-inch electrodes.............................12
Shielded metal-arc welding 3/16-, 7/32,1/4-inch electrodes............................................ 12
5/16-, 3/8-inch electrodes....................................... 14
Atomic hydrogen welding .................................................. 10-14
Carbon arc welding ............................................................. 14
Soldering ............................................................................... 2
Torch brazing ........................................................................ 3 or 4
Light cutting, up to 1 inch .................................................... 3 or 4
Medium cutting, 1 inch to 6 inches .................................... 4 or 5
Heavy cutting, 6 inches and over ...................................... 5 or 6
Gas welding (light), up to 1/8 inch ..................................... 4 or 5
Gas welding (medium), 1/8 to 1/2 inch ............................. 5 or 6
Gas welding (heavy, 1/2 inch and over ............................ 6 or 8

NOTE: in gas welding or oxygen cutting where the torch produces a high yellow, it is desirable to use a filter or lens that absorbs the yellow or sodium line in the visible light of the operation. This table is from Title 29, Code of Federal Regulations, and part 1910.252, OSHA General Industrial Standards.

The welding operation should be enclosed where possible with suitable curtains or portable screens to prevent people from accidentally exposing themselves to the intense radiation.

General Clothing: the type of clothing required is dependent on the size, nature, and location of the work but the following points provide general protection from the hazards created by welding, cutting, or brazing operations.

Except when engaged in light work, all welders should wear flameproof, gauntlet gloves.

Fire resistant aprons may also be desirable as protection against radiated heat and sparks.

Woolen clothing is preferable to cotton because it is not so readily ignited and helps protect the welder from changes in temperature. Cotton clothing, if used, should be chemically treated to reduce its combustibility. All outer clothing, such as jumpers or overalls, should be reasonably free from oil and grease.

Sparks may lodge in rolled-up sleeves, pockets, or cuffs. It is, therefore, recommended that sleeves and collars be kept buttoned and pockets be eliminated from the front of overalls and aprons. Trousers or overalls should not be turned up on the outside.

For heavy work, fire resistant leggings, high boots, or other equivalent means of protection should be used.

Caps or shoulder covers made of leather or other suitable materials should be worn during overhead welding or cutting operations. Leather skullcaps may be worn under helmets to prevent head burns.

For overhead welding and cutting, or enclosed spaces, ear and respiratory protection may be required.

Where there is exposure to sharp or heavy falling objects, or a hazard of bumping in confined spaces, hard hats or head protectors must be used.

23.3 FIRE PREVENTION

Generally, outdoor cutting and welding is permitted only when the area has been made fire safe or free from combustible and flammable materials. All movable fire hazards in the area must be relocated; when all fire hazards cannot be moved, special safeguards will be installed. In either case, fire extinguishers will be made available on site. Conditions may require a “fire watch.”

Any work involving cutting and welding outside the shop must be approved prior to execution, and after an on site inspection by the Site Safety Officer.

23.4 PERSONNEL

The Site Operations Manager assures that anyone authorized to do welding is fully trained and is completely familiar with the equipment.

23.5 EQUIPMENT

There are a vast number of specific requirements involving the setups of various types of systems, such as standard cylinder equipment, cylinder manifolds, service piping systems, acetylene generators, etc., and the special safety mechanisms required on each. Detailed descriptions of the specific operating procedures, safety mechanisms, setups, etc., will be available.

23.6 VENTILATION

Because welding operations often generate various forms of gases and fumes, careful consideration must be give to local exhaust ventilation in the welding area.