This training does not attempt to cover all safety regulations or precautions. For additional safety regulations and precautions, see the following standards: American Welding Society (AWS) American National Standards Institute (ANSI) Occupational Safety and Health Administration (OSHA) Compressed Gas Association (CGA)
Safety is all about HABITS!
Safety In Handling Compressed Gas Cylinders
Common welding gas groups:
Common welding gas groups: Oxidizers Oxygen
Common welding gas groups: Oxidizers Oxygen Fuel Gases Acetylene, Propane
Common welding gas groups: Oxidizers Oxygen Fuel Gases Acetylene, Propane Inert Gases Argon, Helium
Common welding gas groups: Mixed Gases (inert & reactive blends) Argon / Carbon Dioxide Argon / Oxygen Argon / CO2 / Oxygen Helium / Argon / CO2
Never use cylinder color as a primary means to identify the contents of a cylinder read the label.
Colors can vary from supplier to supplier!
There are two considerations regarding safety in handling compressed gases: 1. Pressures 2. Properties
1. Pressures With the exception of fuel gases, welding gases are contained in high pressure cylinders. Seamless drawn high carbon steel 2200 psi @ 70 F. HP cylinders are the same construction, just different valves & different gases.
Protector caps must be in place on cylinders when regulators are not attached whether full or empty.
Cylinder valves are vulnerable to being broken off and high pressure cylinders can become a powerful missile if that happens!
Clam shell protector caps are always a good practice, but MUST be in place when the cylinder is in use on a two wheel or tilt back truck.
Regulators must be removed and protector caps in place during transport unless valves are otherwise protected via clam shell caps or protective cage.
Gage covers can also provide additional protection from damage.
Cylinders should not be dragged or rolled on their base. A tilt-back dolly designed for this use must be used.
If multiple cylinders need to be transported within the facility, a skid designed for this must be used.
Do not move cylinders with a regulator attached. Do not lift cylinders by the cap.
Acetylene cylinders must always stand in the upright position at all times in storage, in use, and in transport.
Cylinders must never free stand, but must be chained securely to a stable object such as a wall, cylinder truck or on a welder undercarriage.
This is NOT secure!
Compressed gas cylinders should be stored in an area protected from traffic (vehicles, fork trucks), or a safety cage or bump rail must be used.
Never store oxygen or fuel gas cylinders in an enclosed area open air ventilation is required.
Cylinders should not be stored in extreme damp conditions, or in corrosive environments.
Oxygen and fuel gas cylinders must be separated from combustible materials by at least 20 feet. Keep oxygen-acetylene equipment at least 20 feet away from oil, solvents, paint, or other flammable materials. Cylinders (especially oxygen and fuel gas) must be protected from welding and cutting sparks at a distance of at least 20 feet.
Fuel gas cylinders in storage (empty or full) must be separated from oxygen and other high pressure cylinders by a minimum distance of 20 feet or by a 5 high fire wall barrier having a fire resistant rating of at least a half hour.
WHY? 1. To prevent oxygen and fuel gas from being in contact with each other in the event of a leaking cylinder valve. 2. To protect high pressure cylinders from contact with flames and heat created from a fuel gas cylinder fire.
Cylinders are considered in storage (empty or full) unless they are connected to an apparatus or in transport.
Construction site standards require disassembly AND separation of oxygen and fuel gas cylinders if equipment will not be used within 24 hours of last use unless a 5 high fire wall barrier having a fire resistant rating of at least a half hour divides them.
Full and empty cylinders must be stored separately and identified by signage to prevent confusion.
Compressed gas cylinders must be protected from the possibility of an arc strike!
If an arc strike occurs on a high pressure compressed gas cylinder, the wall can be weakened or a crack eventually form causing a devastating explosion!
Never leave a stick welding electrode in a stinger, and make sure insulators are in place to prevent an arc strike!
Hoses on oxy-fuel equipment should be hung away from the cylinders to prevent a flame from contacting them in the event of a leak being ignited.
Proper Hose Wrap
Cylinders should always be visually inspected as they arrive from the vender to check for arc strikes, scrapes, & dents.
Cylinders must be hydrostatically tested at least every 10 years.
2. Properties Biggest concern = Oxygen & Fuel Gases
Properties of Oxygen 1. Non-flammable 2. Supports combustion 3. Accelerates combustion 4. Lowers kindling point
Properties of Oxygen
Biggest danger is mixing oil and oxygen in a confined space
Store oxy-fuel equipment in an area free of oil and dust, ideally with the ends of hoses and fittings covered.
Never use oxygen as a substitute for compressed air.
Oxygen and acetylene cylinders must never be transported in an enclosed vehicle (ie: car trunk).
Oxygen and acetylene cylinders must never be transported in an enclosed vehicle (ie: car trunk).
A few operational points Inspect all cylinders, valves, regulators, hoses, torches and other equipment prior to use. Before attaching a regulator to a high pressure cylinder, briefly crack open the cylinder valve to blow out dust trapped in the valve (standing away from the outlet). When opening the cylinder valve, stand to the opposite side of the outlet and open the valve SLOWLY.
Never completely empty a compressed gas cylinder. (25 psi minimum for high pressure, 50 psi for Acetylene) Do not attempt to repair regulators. Return to vender for qualified repairs.
Repair or replace damaged regulators and gages and those which are malfunctioning.
Perform a leak-down test pressurize the system, check cylinder pressure, and close cylinder valves. Wait 20 minutes and see if pressure has dropped. If pressure has dropped, see #10. Locate the source of leaks by applying an approved leak test solution at all connections.
Note: Never use Teflon tape to seal a leak! If the fitting is leaking, it s due to a damaged seat!
Check the condition of O-rings at torch mixer! (Only torch manufacturer s 0-rings)
Electric Arc Welding Safety
The first rule in electric arc welding safety is to NEVER become a better electrical conductor than the material you are welding!
Be certain your body is insulated from live electrical parts & connections; Stay dry and use insulated welding gloves that are dry and not torn.
Never use electrode holders or guns with broken insulators, or welding cables that are cut, frayed at connections, or poorly spliced. If cables are to be repaired, use approved high voltage shrink tube.
Never tie cable leads together to gain length, unless securely connected and properly insulated.
Never wrap cable leads around your body or around the welding machine, and be sure cable is not exposed.
Remove cable from the equipment or undercarriage when welding, and leave it uncoiled. Use whip quick connectors to allow the shortest cable leads possible.
Never change welding current adjustment or polarity when machine is under load. Continuous crank adjustment Rectifier Polarity Switch
Be sure of a proper welding ground: - whenever possible, face the ground. - ground your work securely to prevent stray welding current. - do not ground through bolted connections. - do not ground through rusted or coated surfaces. - ground as close to the arc as possible. - ground must be solid if spring is weak, use a clamp to hold securely.
Poor electrical connection!
Never allow a lift chain to be part of the welding circuit unless it is equipped with an insulator bushing. Or, use a lift sling.
When using the Shielded Metal Arc Welding process (stick), electrodes / stubs should always be removed from the holder when it is not in the operator s hand.
Be certain to turn OFF the equipment when not in use.
Always wear ANSI Z87.1 approved safety glasses!
Always wear appropriate PPE (personal protective equipment) when welding or cutting. Protect your body from arc flash UV, spatter, and fire hazards by being certain your skin is not exposed, and by wearing flame resistant clothing (FRC) no synthetics.
Use protective screens / barriers to protect others from UV arc flash and sparks (preferably translucent).
Protect your eyes and face from arc UV with a welding helmet fitted with the proper filter plate for the job (never less than a #10 filter for continuous arc welding). Auto Helmet Standard Helmet
Never use a helmet that is cracked, or which has a cracked or pitted filter plate. Be sure a clear plastic cover plate is in front and behind the filter plate.
Keep your head away from the arc area, and provide sufficient ventilation or exhaust to keep fumes and gases from your own and other s breathing zone. Portable Exhaust
Cartridge respirators will need to be worn where ventilation is not available or is not adequate for the conditions. P100 Respirator
Welding in confined spaces requires special fresh air ventilation respirators due to conditions of oxygen starvation and displacement.
Plasma cutting and some welding of Stainless Steel produces a dangerous fume called hexavalant chrome. Proper exhaust must be used and personal fume protection must be worn.
Never cut painted, plated, or coated parts or those which have been in contact with hazardous chemicals unless special ventilation precautions are taken (ie: fresh air respirators). Welding galvanized (zinc coated) materials can result in fume fever. Many degreasing compounds may produce deadly gases when subjected to a flame or arc.
If you should develop symptoms of nausea, dizziness, or headache seek medical attention immediately!
OTHER CONCERNS Hot work permits required before welding is done in a maintenance environment. Remove all potential fire hazards from the area. When welding must be done in an area susceptible to fire, have a fire watcher standing by with a fire extinguisher ready. Aerosol cans must be kept away from the welding area. Keep butane lighters out of the work area!