EHS Alert - Arc welding safety
Arc welding is a type of welding that uses a welding power supply to create an electric arc between an electrode and the base material to melt the metals at the welding point. They can use either direct (DC) or alternating (AC) current and consumable or non-consumable electrodes.
Before starting actual arc welding, the operator should be fully aware of the dangers involved. The high temperature arc and hot metal can cause severe burns. In addition the electric arc itself provides Health & safety hazard.
When welding with the electric arc, there is added danger that the small globules or droplets of molten metal may leave the arc and fly in all directions. These sparks range in temperature from 2000 ° to 3000° Fahrenheit and in size from very small to as large as ¼ inch. They present a personal burn hazard plus a fire hazard if they fall on inflammable material.
The welding operator needs to protect himself, by means of a helmet and other protective devices from the harmful rays of the arc and flying sparks. The filter plates in the welding helmet will remove 99% of the harmful rays if the proper shade lens is used.
Other dangers associated with electric arc welding are:
a. Electric shock - which may be caused by standing in damp areas, welding without gloves, bare cables, un-insulated holder, welder in wet condition etc.
b. Harmful fumes - given off in welding process especially when welding on galvanized or other coated materials.
The operator should be suitably trained with all safety precautions and take care to adequately protect himself at all times against any hazards associated with arc welding by wearing protective clothing and equipment, working in dry conditions, providing adequate ventilation and in general using good common sense.
Following is a list of safety precautions that should be observed in the use of the arc welding equipment.
a) Electric Shock
1. Make sure machine is properly grounded.
2. Ensure that return earthling current is drawn from the job itself which is supposed to be welded.
3. Proper gauge of welding cable to be used as Return earthling current.
4. Portable ovens and other stationed ovens must be properly earthed.
5. Welder must be “Dry” physical condition during the course of welding
6. Never permit “live” parts of the electric welder to touch bare skin or wet clothing.
7. Do not cool electrode holders by emersion in water.
8. Turn off power supply when welding activity is not in use.
9. Do not stand on wet areas while welding.
10. Wear leather gloves.
11. Make sure cable are covered and in good condition.
12. Make certain that electrode holders are properly insulate
b) Burns :-
1. Protect eyes and face from flying particles of slag by use of proper welding shield
2. Wear adequate protective clothing.
3. Always wear leather gloves.
4. Wear high top shoes.
5. Keep collar, shirt pockets, etc. buttoned.
6. Do not touch the electrode or metal where welding has taken place.
7. Handle hot metal with pliers or tongs.
8. Keep electrode stubs properly disposed of.
C) Radiant Entry ( Ultra violet rays etc...)
1.Use a welding helmet with the correct shaded welding glasses in good condition.
2. Wear suitable clothing—do not leave bare skin exposed to the rays of the arc.
3. Do not strike the arc without covering the face and eyes. Warn others before striking the arc.
Avoid looking directly at the arc where others are welding without proper eye protection.
d) Gases & Fumes
1. Work only in well-ventilated areas.
2. Take utmost care when working on metals covered with lead or zinc, refer MSDS (Material Safety Data Sheet).
3. If working in a confined area ensures the proper ventilation prior to start welding also use suitable respirator or other approved breathing devices as per job nature.
e) Combustible Materials :-
1. Keep shop clean in areas where welding is to be done.
2. Do not weld near combustible materials of any kind.
3. Never weld on covered containers which may have held combustible and may lead to explode.
F) Fire Protection :-
1. Be familiar with location and types of fire extinguishers
2. Report any unsafe conditions that might start a fire.
3. Do not weld near inflammable materials.
4. Ensure sufficient clearance prior to weld near electrical fittings or lines, follow LOTO (Lockout/Tagout).
(Report all accidents immediately
Remember :- Accidents analysis helps in avoiding further accidents)