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Copyright Progressive Business Publications
Welding, Cutting and Brazing
Copyright Progressive Business Publications
Safety Hazards of Welding
Fire and explosions
Compressed gases and cylinders
Confined spaces
Electrical hazards
Dangerous machinery
Trips and falls
Copyright Progressive Business Publications
Health Hazards of Welding
Welding fumes and smoke
Heat and sparks Visible light,
ultraviolet andinfrared radiation
Musculoskeletalinjuries
Noise
Copyright Progressive Business Publications
Fire Prevention: Basic Precautions
Asses the fire hazards If object to be welded or cut can’t be easily
moved, remove all fire hazards in vicinity If object and fire hazards can’t be moved, use
guards to confine heat, sparks and slag If these requirements can’t be met, then
welding shouldn’t be done Have fire extinguishers ready for instant use
Copyright Progressive Business Publications
Special Precautions: Fire Watch
Purpose: detect and extinguish smoldering fires Required for locations where more than a minor
fire might develop or:– Appreciable combustible materials closer than 35
feet to operation OR more than 35 feet away, but easily ignitable by sparks
– Wall of floor openings expose combustible materials within a 35-radius
– Combustible materials on other side of walls/ceilings Maintained for at least 1/2 hour after completion
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Fire Prevention: Welding is Prohibited in Certain Areas
Areas not authorized by management
Buildings with impaired sprinkler systems
Areas with explosive atmospheres
Areas where explosive atmospheres may develop
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Fire Prevention: Used containers
Make sure used drums barrels, tanks or other containers have been thoroughly cleaned
Disconnect pipes or connections tothe container
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Personal Protection: Fall Protection
When working at heights– Use railings, safety belts,
lifelines or other safeguards– Protect workers below
from falling sparks or slag
Place welding cables and other equipment clear of passageways, ladders or stairways
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Personal Protection: Eye Protection
Use helmets, shields and goggles during arc welding or cutting
Use goggles or other eye protection duringgas welding or oxygen cutting operations
Shield other from welding light with an individual booth or screen, if practical
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Personal Protection: Eye Protection - Shading Requirments
Shielded metal arc welding 10
Gas shielded arc welding (non-ferrous)11
Gas-shielded arc welding (ferrous)12
Torch Brazing 3 or 4
Heavy cutting (6 inches & over) 5 or 6
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Personal Protection: Clothing
Welding gloves, gauntlets and sleeves Flame resistant aprons High-cut safety boots and leggings Shirts: heavyweight, wool, sleeved, collars
buttoned, no pockets Pants: no cuffs and long enough to extend
over boots For overhead work: shoulder capes, skullcaps,
ear protection
Copyright Progressive Business Publications
Personal Protection: Ventilation
Ensure adequate ventilation prior to working
Use local exhaust ventilation where needed
Respirators worn:– When cancer-causing agents present – During certain confined space work
Materials requiring extra precautions: fluorine compounds, zinc, lead, beryllium, cadmium, mercury, cleaning compounds, stainless steel
Copyright Progressive Business Publications
Before Entering Confined Spaces
Acquire confined space permit Ensure adequate ventilation
– Test before entering for flammable/toxic gases or oxygen deficiency
– If flammable or toxic gases are present - ventilate– If ventilation is inadequate, use a respirator
Disconnect pipes, ducts and power lines Leave gas cylinders and welding machines
outside of the confined space
Copyright Progressive Business Publications
Confined Spaces
Attendant must observe the welder and be ready to execute a pre-planned emergency rescue plan
If arc welding is suspended for a period of time: – Remove electrodes from holders– Disconnect machines from power sources
If gas welding is suspended for a period of time: – Close the torch valves– Shut off the gas supply to the torch– Remove the torch and hose, if practical
Copyright Progressive Business Publications
Cylinder Storage
In a well-ventilated, dry, location >20 ft away from highly combustible materials such as oil
Away from sources of heat and ignition Away from high traffic areas and exits Stored in compatible groups
– Oxygen and Acetylene: separated by 20 feet or a 5-foot wall with 1/2-hour fire rating
In upright position with valve protection caps on and secured with straps or chains
Copyright Progressive Business Publications
Cylinder Handling
Never work with unidentified cylinders Refer to MSDS for specific hazards, special
handling instructions, emergency response and first aid information
Inspect cylinders for damage prior to work When transporting:
– Secure to wheeled hand cart with theregulator removed
– Never use valve caps to lift the unit– Don’t drop or bang
Copyright Progressive Business Publications
Cylinder Handling (cont’d)
Valve protection caps must always be in place when not in use - empties included
If cylinder must be left unattended, close cylinder valve and shut down system
Keep cylinder in an upright position atall times
Keep cylinders and valve caps free from oilor grease
Mark work areas when finished work
Copyright Progressive Business Publications
Placement of Cylinders During Use
Cylinders must be placed where sparks, hot slag or flames can’t reach them
If that’s not possible, use fire-resistant shields
Keep cylinders away from electrical circuits or objects used for grounding
Cylinders must be placed outside any confined space
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To Begin Work
“Crack” the cylinder valve Ensure regulators are compatible, clean and
in good condition before attaching them Make sure hoses and connections are secure When opening the cylinder valve, stand to the
side and open s-l-o-w-l-y. Keep any vendor-supplied keys in place Keep the valve within easy reach
Copyright Progressive Business Publications
Purge Hoses Prior to Lighting
First, acetylene– Open acetylene
cylinder valve 3/4 turn– Open torch valve
1/4 turn– Adjust to working
pressure with regulator screw
– Close torch valve
Then, oxygen– Open oxygen cylinder
valve fully (slowly)– Open torch valve
1/4 turn– Adjust to working
pressure with regulator screw
– Close torch valve
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Lighting and Shutting the Torch
To light torch:– Reopen acetylene
torch valve– Light with friction
lighter: • Never matches• Never cigarettes
– Open oxygen 1/4 turn and adjust flame
To shut off torch:– Close torch valves:
acetylene then oxygen– Close cylinder valves:
acetylene then oxygen– Open both torch valves
to release pressure– Shut off regulator
adjusting handle– Close torch valves
Copyright Progressive Business Publications
For Safe Use of Acetylene
Never used at pressure in excess of 30 psi absolute or 15 psi gage
Never open acetylene valve more than 1 1/2 turns.
Never use copper fittings or connections
Copyright Progressive Business Publications
Arc Welding and Cutting
Ensure the work area is dry Double-check the grounding Check connections to the machine
– Make sure work lead is firmly attached – Keep metal clamps free from debris
Never use cables with splices within 10 feet of the holder
Replace cables with damaged insulation or exposed bare connectors
Copyright Progressive Business Publications
Arc Welding and Cutting (cont’d)
Spread out cables Never coil cables around your body Never strike an arc on a gas cylinder Never change polarity switch during
operation If work must be stopped, disconnect power
source and remove electrodes Store holders where they can’t make
unwanted contact
Copyright Progressive Business Publications
Summary
Safety and health hazards = special precautions Fire prevention Personal Protection
– Fall safety– PPE– Confined spaces– Ventilation
Use of compressed gas cylinders Safe welding procedures
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