The Basics of Welding Safety

Proper welding safety starts with familiarizing yourself and other operators with the welding equipment and the manufacturer’s recommendations. Take the time to read the operator’s manual thoroughly and follow all of the safety, operation and maintenance instructions it contains. Keep the manual handy so new users can acquaint themselves with the machine. Should the operator’s manual become lost or damaged, request a new one from the manufacturer. Miller Electric and many other manufacturers provide product manuals on-line. Spanish and French language versions are available for some of the most common products.

The Well-Dressed Welder

Arc welding produces sparks and emits intense visible and invisible rays that pose several hazards to unprotected skin and eyes. When welding, adequately protect your skin. Shorts, short sleeves, open collars all leave you vulnerable to burns from both flying sparks and the arc rays. Wear only flame-resistant clothing, and button your cuffs and pockets to prevent them from catching sparks. Pants cuffs, too, can catch sparks and should be avoided.

Figure 1: The well-dressed (or safely dressed welder) no longer has to use a clumsy, ill-fitting jacket. Modern welding garments are more functional, flexible and better fitting. Note that once the welder dons the helmet, he will have no skin exposed to sparks or arc burns. A flame resistant jacket is completely buttoned, allowing no pockets or spaces for a spark to catch. A welding bandana protects the top of his head from sparks. An auto-darkening welding helmet decreases the chance for repetitive stress injury to one’s neck and can adjust to changing arc parameters conditions.

With respect to footwear, high top leather shoes offer the best protection. Tennis shoes and other cloth shoes are inadequate; they can catch a spark and smolder unnoticed and their components can melt and stick to your skin.

Always wear proper gloves when welding or handling recently welded material to protect yourself from sparks, arc burns and the heat from the workpiece. Remember, even a quick tack weld requires the use of a welding helmet and appropriate apparel (see Figure 1).

Although the above sounds obvious, a common fault among welders is not wearing the right safety equipment. While expediency is one reason often given, some welders complain that the common, one-size-fits-all apparel is too bulky, heavy and restricting and that gloves, especially in TIG applications, do not provide the necessary sensitivity and flexibility.

Figure 2: Welding gloves are now available in different styles to meet the demand of different welding applications. The medium duty MIG gloves shown here (left) offer ergonomically curved fingers and padded palm for increased comfort and rugged construction for increased longevity. The TIG gloves (bottom center) are made from goatskin, which provides excellent dexterity, comfort and durability. Metal working gloves (top center) and heavy duty MIG gloves widen the choices available to the welder.

While that may have been true in the past, leading manufacturers now offer safety apparel that address the welder’s comfort and specific needs.

"The welding industry is moving beyond the cookie cutter, one-size-fits-all idea of safety products, demanding garments that are safe from a functional standpoint, yet attractive with a better fit,” says John Swartz, welding components & consumables product manager, Miller Electric Mfg. Co.

Lightweight flame resistant cloth, pigskin leather and combinations of the two offer the welder better protection, even when welding overhead, and increased ease of movement than ever before. For additional flexibility, some jackets feature snaps for the addition of a leather bib or apron.

Gloves in small to extra-large sizes with ergonomically curved fingers are now available for specific welding processes. Heavy duty MIG/Stick gloves, medium MIG gloves and TIG gloves that provide that added dexterity and touch are just some of the recent additions to the field (see Figure 2)

Helmets

Even a brief exposure to the arc’s radiation may be damaging to your eyes, causing symptoms from a burning sensation to temporary blindness. Repeated exposure can lead to permanent injury. Always wear proper eye protection when welding or when exposed to a welding arc.

If you use a standard, fixed shade helmet, pick one that has a lens shade appropriate for your welding application. OSHA offers a guide for choosing the correct lens based on welding criteria. If your weld parameters and materials don’t vary, a fixed-shade lens may be right for you. However, if you’ll be switching processes, materials or parameters, an auto-darkening helmet may be your best solution.

Figure 3: Auto-darkening helmets provide many benefits, including increased efficiency, decreased chance for repetitive stress injury and responsiveness to changing arc quality. Attractive graphic designs promote safety while allowing the wearer to express his or her personality.

All auto-darkening helmets must meet ANSI standards, the most recent being ANSI Z87.1-2003. When an arc triggers the sensors on an auto-darkening helmet, the lens darkens in a fraction of a second. Some fixed-shade auto-darkening helmets darken to a #10 shade with a reaction time of 1/2000 to 1/3,600 of a second and are not adequate for frequent tack welds, TIG welding and other industrial applications.

Industrial grade helmets react at speeds of 1/10,000 of a second or higher to prevent eye fatigue and arc flash symptoms, and have adjustable shades settings of #9-#12 or #13. (Miller Elite auto-darkening helmets react in 1/20,000 of a second, with shade settings of #8 to #13.) Industrial grade helmets, such as the Miller Elite series, will also have adjustable sensitivity and delay controls (see Figure 3).

Adjustable sensitivity is useful when welding at low amperages, especially TIG, when the light isn’t as bright as other processes. Adjustable delay controls how long the lens remains darkened after the arc stops. When tack welding, a short delay may be desired, while a longer delay may be desirable after welding at very high temperatures. Even when not activated, the lens provides UV/IR protection and usually has a light state of a #3 or #4 shade, which is relatively easy to see through.

Auto-darkening helmets provide some other important benefits also. With a fixed-shade helmet, the welder positions the gun, torch or electrode and then jerks his head down to bring the helmet into place. This may lead to neck injury through the repeated motion, especially for welders who perform a series of tack welds. For the novice or person who welds infrequently, the jerking action can cause him to move out of position and lead to a weld defect. An auto-darkening helmet allows the welder to keep the helmet in place while positioning the electrode, leading to better positioning and relieving some of the stress from the welder’s neck.

Work Environment

You must also protect others in the welding area. Use a weld screen to ensure passersby will not be subjected to the arc flash.

Keep your work area free from clutter. This promotes safety and helps increase efficiency by making necessary equipment easier to find. Remove rags, paper or anything else that could be a fire hazard. Cables and hoses can create a tripping hazard. Organize the workspace to minimize the number of cables underfoot and position them so they are not in danger of being run over or stepped on (see Figure 4). If possible, suspend hoses off the ground and coil up excess hose to prevent kinks and tangles. MIG welding with a wire feeder that allows remote control of the power source is one way to free up space in the welding cell.

Figure 4: By using the remote control capability of its Miller Delta-Fab welders, Godwin Mfg., keeps the power sources out of the welding cells and hides the hoses and cables underground where they can’t be tripped over or run over by a forklift. The result is a safe and efficient work area.

Examine hoses regularly for leaks, wear and loose connections. To check for leaks, immerse pressured hoses in water (bubbles will indicate leaks.) Repair a leaky or worn hose by cutting out damaged area and splicing. Do NOT use tape.

Avoid working in wet conditions, since water conducts electricity, and insulate yourself from the work and the ground by standing on a dry rubber mat or similar non-flammable material. Connect the workpiece to a proper earth ground and connect the frames of all electrically powered machines to a properly grounded disconnect switch, receptacle or other appropriate ground. Always double-check the installation and verify proper grounding. Never use chains, wire ropes, cranes, hoists and elevators as grounding connectors.

When using gas cylinders, chain them securely to a stationary, upright support or cart at all times. When moving or storing a cylinder, fasten the threaded protector cap to the top of the cylinder. Doing so shields the valve system from impact damage.

Immediately remove a faulty regulator from service for repair by a manufacturer’s designated repair center. Do not attempt to repair it yourself.

Use only recommended ferrules or clamps designed to connect hoses to fittings—never use ordinary wire or other substitutes.

 

arrow
arrow
    全站熱搜

    bairdben 發表在 痞客邦 留言(0) 人氣()