3. Welding and Thermal Cutting Flashcards
What are the three basic processes of welding?
Oxyfuel welding and cutting
Resistance welding and cutting
Electric arc welding and cutting.
What is the required level of training for a worker performing welding tasks?
Although there is a trade journeyman for welding, it is not required by OHS legislation.
What are the four main OHS concerns with oxyfuel welding?
Fire & explosion.
Burns from the flame, hot metal, flying spatter/slag.
Health hazards: toxic gasses, vapours, inhaled particulates, UV radiation, intense visible light.
Manual handling of materials and equipment.
List engineering controls that reduce fire/explosion risks in compressed gas cylinders, hoses, regulators, and torches when used in oxyfuel welding.
CSA cylinders.
Design standards for regulators, hoses, and torches.
Flashback arrestors.
Proper storage and securing of cylinders.
Colour-coded hoses.
Right-hand and left-hand threads to avoid crossing hoses.
Describe in detail the 6 PPE recommended for oxyfuel welding.
CSA eye/face protection. (flying debris, UV radiation, visible light)
Jacket/coveralls/sleeves of
fire resistant material (such as cotton or leather).
Fire-resistant gloves covering wrists (such as leather).
Fire-resistant footwear (such as leather).
Fire-resistant hat/cap (such as cotton).
Respirators PRN if insufficient LEV/GEV.
What type of material shouldn’t be worn when welding? Why?
Synthetic fibers.
Synthetic materials can melt or combust more easily than natural fibers, such as cotton or leather.
Why must oxyfuel equipment be checked for leaks, defects, oil, and grease before every use?
Leaks pose a fire risk. Oil and grease can combust, and may also allow for leaks.
What are the five safety hazards and two health hazards common to most welding and thermal cutting processes?
Heat
Compressed gasses
Fire
Electricity
Flying splatter/slag
Gases, vapours, and particulates
Optical radiation (UV, IR, Visible light)
What are five controls used in welding to reduce the risk of heat?
Marking work as HOT with a soapstone marker
Provide containers for disposing of hot welding rod tips (common regulatory requirement)
Wearing leather or fire-resistant PPE
Restricted access to work area
Ensuring high level of skill in the workers
List 7 controls to reduce the risks of compressed gasses in welding/thermal cutting applications.
Use CSA or ANSI approved cylinders, regulators, and hoses.
Conduct regular cylinder inspections
Secure cylinders when in use and in storage
Cap cylinder valves when not in use
Ensure fittings are free of grease and debris
Check components for leaks
Train workers on safe procedures for changing cylinders/regulators
List 5 controls to reduce fire risks associated with welding and thermal cutting.
Provide fire extinguishers
Avoid hot work near flammable or combustible materials
Build welding booths out of non-combustible materials
Use flashback arrestors
If materials to be welded have been in contact with flammable materials, ensure fully cleaned or rendered inert prior to welding/cutting.
List 6 controls to reduce the risks of electrocution associated with welding equipment.
Ensure equipment meets electrical code requirements
Use qualified people to maintain equipment
Inspect equipment for condition
Use equipment that encloses electrical components
Use equipment that has insulation on electrical components
Ground the work/equipment
List three controls to reduce risks from splatter/slag when welding/thermal cutting.
Use CSA eye/face protection
Use appropriate heat-resistant gloves/hat/clothing
Ensure workers have a high degree of skill to reduce the amount of splatter/slag produced.
Discuss health hazards and controls associated with gases, vapours, and particulates in welding.
Metals heated in welding can be vaporized, resulting in airborne fumes. Some metal fumes are known to be harmful to human health.
Shielding gases are inert, but can displace oxygen.
Flux cores can be vaporized, resulting in airborne fumes. Some of these fumes are harmful to human health.
Controls include
- LEV
- Use of materials/processes/techniques that produce the least fumes/etc.
- Removal of coatings/adhesives from work pieces prior to welding.
Discuss optical radiation hazards and controls associated with welding.
Intense optical radiation can be produced during welding and thermal cutting.
Exposure to intense flashes of optical light is called flash burn. It can lead to conjunctivitis and cataracts (especially infrared).
Controls:
- CSA eye/face protection
- Minimal skin exposed to optical radiation
- Use welding shields around work area to block optical radiation
- limit bystander access to work area
