Welding is mainly used to join metals. It is an unavoidable task which is carried out daily in different forms in our different establishments.
If safe welding is not carried out, then the welder and people working around could be seriously affected.
There are different methods of welding, and they includes:
◾Shielded metal arc welding (SMAW):
This is known as “stick welding or electric welding”, it uses an electrode that has flux around it to protect the weld puddle.
The electrode holder holds the electrode as it slowly melts away. Slag protects the weld puddle from atmospheric contamination.
◾Gas tungsten arc welding (GTAW):
It is also known as TIG (tungsten, inert gas), uses a non-consumable tungsten electrode to produce the weld.
The weld area is protected from atmospheric contamination by an inert shielding gas such as argon or helium.
◾Gas metal arc welding (GMAW):
It is commonly termed MIG (metal, inert gas).
It uses a wire feeding gun that feeds wire at an adjustable speed and flows an argon-based shielding gas or a mix of argon and carbon dioxide (CO2) over the weld puddle to protect it from atmospheric contamination.
◾Flux-cored arc welding (FCAW):
This is almost identical to MIG welding except that it uses a special tubular wire filled with flux.
It can be used with or without shielding gas, depending on the filler.
◾Submerged arc welding (SAW):
This method of welding uses an automatically fed consumable electrode and a blanket of granular fusible flux.
The molten weld and the arc zone are protected from atmospheric contamination by being “submerged” under the flux blanket.
◾Electroslag welding (ESW):
This is a highly productive, single pass welding process for thicker materials between 1 inch (25 mm) and 12 inches (300 mm) in a vertical or close to vertical position.
◾Electric resistance welding (ERW):
This is a welding process that produces coalescence of laying surfaces where heat to form the weld is generated by the electrical resistance of the material. In general, an efficient method, but limited to relatively thin material.
MAJOR HAZARDS OF WELDING
The major hazards that comes with welding activity includes:
- Fire and explosions: Welding activity is an hot job which requires hot job permit. If necessary precautions are not taken, it could result in fire outbreak or explosion.
- Welding fumes and gases: Welding fumes are a combination of various metals which most times are very toxic to health.
- Electric shock: A welder can get trapped if he mistakenly get in contact with electric current transmission line.
- Burns: Spatters from the welding surface could cause burns if adequate welding clothing is not used.
- Musculoskeletal disorders: This could result from repetitive adoption of poor working posture.
WAYS TO ENSURE SAFE WELDING
I will divide these safety measures into three (3) phases:
Before commencing welding activity:
It is needful that every welding activity is well planned to ensure safe welding. It is at this planning phase that we can identify possible hazards involved and the precautionary measures to take.
Welding is a high risk task, and it will need a permit to work before commencement.
This permit will take into consideration the welding environment, the emergency tools like a workable fire extinguisher.
The availability of a fire watch, other welding accessories like the fire blanket, welding shield, face shield, etc will also be captured in the permit to work.
Also choice of welding location should be dependent on the ventilation level, since good ventilation is very paramount in safe welding.
If the location of welding does not favour natural ventilation, artificial ventilation should be provided.
My candid advice to welder: Always position opposite the direction of the wind during welding. The wind will tend to blow the welding fumes away from you, instead of bringing it to you.
Compliance to all safety precautions must be enforced to enhance safe welding, with the use of all necessary personal protective equipment. Welders should be advised to adopt good working posture. (They should work with their head and not their back)
The entire welding environment must be cleared to avoid possible development of fire. The fire watch must be on ground, at least 30 minutes after the welding activity. Without these, safe welding will not be achieved
WELDING STANDARDS ON THE USE OF PPE
According to OSHA 29 CFR 1910.252 (b)(2)(ii)(B), “Helmets and hand shields shall be arranged to protect the face, neck and ears from direct radiant heat from the arc.”
When arc cutting and arc welding with an open arc, OSHA requires operators to use helmets or hand shields with filter lenses and cover plates.
Nearby personnel viewing the arc must also be protected. Safety glasses with a shade 2 lens are recommended for general-purpose protection for viewers.
When resistance welding or brazing, operators must use face shields, safety glasses or goggles, depending on the particular job, to help protect their faces and eyes from welding hazards.
According to ANSI Z49.1-2012, Welding and Cutting (4.3), “appropriate protective clothing for any welding or cutting operation will vary with the size, nature and location of the work to be performed.
Clothing shall provide sufficient coverage and be made of suitable materials to minimize skin burns caused by sparks, spatter or radiation.
Covering all parts of the body is recommended to protect against ultraviolet and infrared ray flash burn.”
The ANSI standard requires all welders and cutters to wear protective flame-resistant gloves, such as leather welder’s gloves, which provide the heat resistance needed for welding.
GENERAL SAFE WELDING PRECAUTIONS
- Do not permit unauthorized persons to use welding or cutting equipment.
- Do not weld in a building with wooden floors, unless the floors are protected from hot metal by means of fire resistant fabric, sand, or other fireproof material.
- Remove all flammable material, such as cotton, oil, gasoline, etc., from the vicinity of welding.
- Before welding or cutting, warn those in close proximity who are not protected to wear proper clothing or goggles.
- Do not leave hot rejected electrode stubs, steel scrap, or tools on the floor or around the welding equipment. Accidents and/or fires may occur.
- Keep a suitable fire extinguisher nearby at all times. Ensure the fire extinguisher is in workable condition.
- All necessary PPE must be used, they include: Helmets and Shields, Safety Goggles, Protective Clothing, Safety boots. Safety clothing should be worn properly; the trouser of the safety clothing should not be folded since welding spatter can be trapped in there resulting to burns. Use of rain boot should also be avoided.
STAY SAFE !!!