Welding, Cutting, And Brazing

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Welding, Cutting, And Brazing
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Session Objectives

• You will be able to
• Identify major safety and health hazards of
  welding
• Select appropriate PPE for welding, cutting, and
  brazing
• Implement controls to prevent or control fires

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Types of Welding

• Welding includes 60 or more process variations
• Electric welding and oxy-fuel gas welding
• Welding/cutting occurs at most businesses at some
  point

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Welding Hazards

• Firescaused by unsafe welding or cutting
  operations
• Burns
• Electric Shock
• Light radiation ultraviolet, infrared, and
  intense visible light
• Air Contaminants (gases, fumes, smoke)

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Basic Fire Prevention

• Inspect welding area before starting
• Remove fire hazards
• Install guards
• Welding or cutting must NOT take place unless
  hazards removed or guards installed
• Obtain a hot work permit before starting
  operations to ensure that all fire hazards are
  controlled
• Post a fire watch person 1/2 hour after operation
  ceases

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Fire Prevention (cont.)

• Never weld in explosive atmospheres
• Do not weld on used containers
• Test potentially explosive containers for
  flammable atmospheres
• Shut off cylinder valves when not in use

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Ventilation

• Three factors govern the amount of contamination
  to which welders may be exposed
• Dimensions of the space
• Number of welders
• Possible evolution of hazardous fumes
• Management must ensure welders have proper
  protection and ventilation

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Oxygen-Fuel Gas Welding

• Acetylene
• Flammable
• Unstable
• Cannot be used above 15 psi
• Oxygen
• Added to support fuel gas flame and obtain high
  temperature for melting steel (welding)

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Basic Rules for Oxy-acetylene Welding

• Ensure the safety fuse plug or disk is functional
• Attach regulator
• Stand to one side of regulator
• Open cylinder valve slowly
• Not more than 15 psi

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Basic Rules for Oxy-acetylene Welding (cont.)

• Purge oxygen and acetylene lines
• Light the acetylene
• Never use oil or grease near oxygen
• Do not use oxygen to clean or blow off dirt or
  clothing
• Keep your work area clean

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Store Gas Cylinders Safely

• The storage area must be well ventilated
• Keep fuel cylinders 20 feet or more from
  combustibles
• Close valves, ensure valves are protected
• Limit inside storage to 2,000 cubic feet
• Store cylinders in the upright position and
  secured from falling
• Separate oxygen from fuel gas

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Follow Gas Cylinder Precautions

• Never lift cylinders by the service valve or
  valve protection (use slings, net, or other
  approved means)
• Keys, handles, and hand wheels must be present
• Use the proper regulator
• Open acetylene valve no more than 11/2 turns
• If in doubt about a cylinder, dont use it

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Use Protective Devices

• Pressure relief valves, backflow preventers or
  check valves
• Flash back arrestors
• Fuel gas hosered (sometimes black)
• Oxygen hosegreen
• Hose protection required
• Pressure-reducing regulators

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Protect Yourself

• Keep working surfaces clean and clear
• Light torches with a striker, not a lighter!
• Wear face and eye protection
• Use safety glasses under welding hood and burning
  goggles with proper shading
• Wear protective body clothing
• Avoid synthetic clothing
• Use leather gloves with gauntlet

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Lens Shades

• Generally, use a 45 shade for
• Torch brazing
• Oxy-fuel gas cutting/welding

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Oxy-Acetylene WeldingAny Questions?

• Any questions about oxy-acetylene welding safety?

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Arc WeldingCommon Processes

• Shielded metal arc welding (stick welding)
• Gas metal arc welding (MIG welding)
• Gas tungsten arc welding (TIG welding)
• Flux cored arc welding
• Submerged arc welding
• Arc cutting
• Plasma arc cutting

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Arc Welding Hazards and Safety Measures

• Hazards
• Arc gives off ultraviolet and infrared rays the
  same as those causing sunburn
• Exposure within several inches to a few feet can
  cause flash burn to eyes and skin
• Safety measures
• Avoid wet or damp areaspromotes electric shock
  hazard
• Avoid oil, grease, and flammables as they pose a
  fire hazard

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Shielding and Flash Screens

• Air must be kept away from weld area
• Shielding protects the integrity of the weld
  joint
• Flux or gas mixture is used as a shield
• Welders need to erect flash screens around them
  to protect others in area

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Maintain Equipment Properly

• Welding machines must be grounded
• Work area must be dry and free of hazards
• Connections must be tightly made
• Cable splices within 10 feet of holder are
  prohibited
• Cables must be maintained and conductors well
  insulated

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Protect Yourself

• Wear welding helmets with proper shading
  depending on type of arc
• DO NOT use brazing goggles
• Wear safety glasses under helmet
• Wear leather gloves with gauntlets
• Use ventilation or respirators
• Wear leather bibs, sleeves, or jackets to prevent
  burns from slag, sparks, and ultraviolet

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Lens Shades

• Generally, use a 1014 shade for
• Shielded metal arc
• Gas metal arc
• Gas tungsten arc

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Arc WeldingAny Questions?

• Any questions about arc welding?

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Key Points to Remember

• Major hazards include
• Fire
• Burns
• Shock
• Toxic exposures
• Follow proper procedures to prevent fires
• Use appropriate engineering controls
• Wear appropriate PPE