welding, cutting and brazing

Welding, Cutting, And Brazing

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Session ObjectivesYou 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


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


Welding Hazards• Fires—caused by

unsafe welding or cutting operations• Burns• Electric Shock• Light radiation—

ultraviolet, infrared, and intense visible light• Air Contaminants

(gases, fumes, smoke)


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


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


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


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)


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


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


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


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, don’t use it


Use Protective Devices• Pressure relief valves,

backflow preventers or check valves• Flash back arrestors• Fuel gas hose—red

(sometimes black)• Oxygen hose—green• Hose protection

required• Pressure-reducing

regulators


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


Lens Shades Generally, use a 4–5 shade for:• Torch brazing• Oxy-fuel gas

cutting/welding


Oxy-Acetylene Welding—Any Questions?• Any questions about oxy-acetylene welding

safety?


Arc Welding—Common 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


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 areas—promotes electric shock hazard

• Avoid oil, grease, and flammables as they pose a fire hazard


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


•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

Maintain Equipment Properly


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


Lens Shades Generally, use a 10–14 shade for:• Shielded metal arc• Gas metal arc• Gas tungsten arc


Arc Welding—Any Questions?• Any questions about arc welding?


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

welding, cutting and brazing

Documents

use business legal reports

smoke business legal

psi business legal reports

point business legal

brazing business legal

unsafe welding

welding hazardsfirescaused

oxyacetylene welding