|
|
SAFETY Mishaps frequently occur in welding operations. In many instances, they result in serious injury to the welder or other personnel working in the immediate area. In most cases, mishaps occur because of carelessness, lack of knowledge, and the misuse of available equipment. Precautions that apply to specific welding equipment are pointed out in the chapters that cover that equipment. In this section we are particularly interested in such topics as protective clothing, eye protection devices, and practices applicable to the personal safety of the operator and personnel working nearby. Proper eye protection is of the utmost importance. This covers the welding operator and the other personnel, such as helpers, chippers, or inspectors, who are in the vicinity of the welding and cutting operations. Eye protection is necessary because of the hazards posed by stray flashes, reflected glare, flying sparks, and globules of molten metal. Devices used for eye protection include helmets and goggles. NOTE: In addition to providing eye protection, helmets also provide a shield against flying metal and ultraviolet rays for the entire face and neck. Figure 3-56 shows several types of eye protection devices in common use. Flash goggles (view A) are worn under the welder's helmet and by persons working around the area where welding operations are taking place. This spectacle type of goggles has side shields and may have either an adjustable or nonadjustable nose bridge. Eyecup or cover type of goggles (view B) are for use in fuel-gas welding or cutting operations. They are contoured to fit the configuration of the face. These goggles must be fitted with a shade of filter lens that is suitable for the type of work being done. NOTE: The eyecup or cover type of goggles are NOT to be used as a substitute for an arc-welding helmet. For electric arc-welding and arc-cutting operations, a helmet having a suitable filter lens is necessary. The helmet shown in view C has an opening, called a Table 3-l.-Recommended Filter Lenses for Various Welding Operations window, for a flip-up filter lens 2 inches by 4 1/4 inches in size. The helmet shown in view D has a 4 1/2-inch by 5 1/4-inch window. The larger window affords the welder a wider view and is especially useful when the welder is working in a confined place where head and body movement is restricted. When welding in locations where other welders are working, the welder should wear flash goggles beneath his helmet to provide protection from the flashes caused by the other welders' arcs. The flash goggles will also serve as eye protection when chipping the slag from a previous weld deposit. Helmets and welding goggles used for eye protection are made from a nonflammable insulating material. They are fitted with a removable protective colored filter and a clear cover lens. NOTE: The purpose of the clear cover lens is to protect the filter lens against pitting caused by sparks and hot metal spatter. The clear lens must be placed on the outside of the filter lens. The clear lens should be replaced when it impairs vision. Filter lenses are furnished in a variety of shades, which are designated by number. The lower the number, the lighter the shade; the higher the number, the darker the shade. Table 3-1 shows you the recommended filter lens shade for various welding operations. The filter lens shade number selected depends on the type of work and somewhat on the preference of the user. Remember, a filter lens serves two purposes. The first is to diminish the intensity of the visible light to a point where there is no glare and the welding area can be clearly seen. The second is to eliminate the harmful infrared and ultraviolet radiations coming from the arc or flame; consequently, the filter lens shade number you select must not vary more than two shades from the numbers recommended in table 3-1. Rule of thumb: When selecting the proper shade of filter lens for electric-arc welding helmets, place the lens in the helmet and look through the lens as if you were welding. Look at an exposed bare light bulb and see if you can distinguish its outline. If you can, then use the next darker shade lens. Repeat the test again. When you no longer see the outline of the bulb, then the lens is of the proper shade. Remember that this test should be performed in the same lighting conditions as the welding operation is to be performed. Welding in a shop may require a shade lighter lens than if the same job were being performed in bright daylight. For field operations, this test may be performed by looking at a bright reflective object. WARNING Never look at the welding arc without proper eye protection. Looking at the arc with the naked eye could lead to permanent eye damage. If you receive flash burns, they should be treated by medical personnel. A variety of special welder's clothing is used to protect parts of the body. The clothing selected varies with the size, location, and nature of the work to be performed. During any welding or cutting operation, you should always wear flameproof gauntlets. (See fig. 3-57.) For gas welding and cutting, five-finger gloves like those shown in view A should be used. For electricarc welding, use the two-finger gloves (or mitts) shown in view B. Both types of gloves protect the hands from heat and metal spatter. The two-finger gloves have an advantage over the five-finger gloves in that they reduce the danger of weld spatter and sparks lodging between the fingers. They also reduce finger chafing which sometimes occurs when five-finger gloves are worn for electric-arc welding. Many light-gas welding and brazing jobs require no special protective clothing other than gloves and Figure 3-58.-Welder's protective clothing. goggles. Even here, it is essential that you wear your work clothes properly. Sparks are very likely to lodge in rolled-up sleeves, pockets of clothing, or cuffs of trousers or overalls. Sleeves should be rolled down and the cuffs buttoned. The shirt collar, also, should be fully buttoned. Trousers should not be cuffed on the outside, and pockets not protected by button-down flaps should be eliminated from the front of overalls and aprons. All other clothing must be free of oil and grease. Wear high top-safety shoes; low-cut shoes are a hazard because sparks and molten metal could lodge in them, especially when you are sitting down. Medium- and heavy-gas welding, all-electric welding, and welding in the vertical or overhead welding position require special flameproof clothing made of leather or other suitable material. This clothing is designed to protect you against radiated heat, splashes of hot metal, or sparks. This clothing consists of aprons, sleeves, combination sleeves and bib, jackets, and overalls. They afford a choice of protection depending upon the specific nature of the particular welding or cutting job. Sleeves provide satisfactory protection for welding operations at floor or bench level. The cape and sleeves are particularly suited for overhead welding, because it protects the back of the neck, top of the shoulders, and the upperpart of the back and chest. Use of the bib, in combination with the cape and sleeves, gives added protection to the chest and abdomen. The jacket should be worn when there is a need for complete all-around protection to the upperpart of the body. This is especially true when several welders are working in close proximity to one another. Aprons and overalls provide protection to the legs and are suited for welding operations on the floor. Figure 3-58 shows some of the protective clothing available to welders. To prevent head burns during overhead welding operations, you should wear leather or flameproof caps under the helmet. Earplugs also should be worn to keep sparks or splatter from entering and burning the ears. Where the welder is exposed to falling or sharp objects, combination welding helmet/hard hats should be used. For very heavy work, fire-resistant leggings or high boots should be worn. Shoes or boots having exposed nailheads or rivets should NOT be worn. Oilskins or plastic clothing must NOT be worn in any welding operation. NOTE: If leather protective clothing is not available, then woolen clothing is preferable to cotton. Woolen clothing is not as flammable as cotton and helps protect the operator from the changes in temperature caused by welding. Cotton clothing, if used, should be chemically treated to reduce its flammability. |
Privacy Statement - Press Release - Copyright Information. - Contact Us - Support Integrated Publishing |