Welding, Cutting, And Brazing: Welding, Cutting, And Brazing


Session Objectives: 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


Types of Welding: 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: 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: 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.): 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: 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: 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: 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.): 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: 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: 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: 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: 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 : Lens Shades Generally, use a 4–5 shade for: Torch brazing Oxy-fuel gas cutting/welding


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


Arc Welding—CommonProcesses: 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: 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: 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


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 Maintain Equipment Properly


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


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


Key Points to Remember: 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