745 Welding, Cutting, and Brazing Safety

Arc Welding/Cutting Equipment

Plasma Arc Welding/Cutting

As mentioned earlier, Plasma Arc Welding (PAW) is a specialized welding technique that generates heat by creating a highly focused, high-temperature electric arc between a tungsten electrode and the metal workpiece. The arc ionizes gas (typically argon), forming plasma, which is an electrically conductive, intensely hot stream used to melt the base metals, forming a joint as they solidify.

Equipment includes: Plasma welding/cutting torch, power supply unit, compressed air or inert gases (argon, nitrogen), air compressor or gas cylinder, and metal work table or cutting bench.

Specific Steps in Operation: The following is a brief list of steps to safely operate the equipment:

1. Inspect Equipment
   • Check the power source, torch, cables, hoses, and air or gas supply.
   • Inspect consumables (electrodes, nozzles, shields) and replace if worn.
   • Ensure proper grounding of the workpiece.
2. Set Up the Machine
   • Select appropriate settings: current, gas type, and flow rates based on material and thickness.
   • Adjust travel speed and arc length as needed.
3. Purge and Test Air/Gas Flow
   • Purge lines to ensure clean and dry air or gas supply.
   • Verify flow rate using gauges or indicators.
4. Start the Arc
   • Position the torch correctly on or near the workpiece.
   • Use the torch trigger or foot pedal to initiate pilot arc, then transfer to cutting/welding arc.
5. Perform Welding/Cutting
   • Maintain proper torch angle, height, and travel speed for clean, controlled cuts or welds.
   • Monitor arc stability and adjust as needed.
6. Shut Down
   • Release the trigger to stop the arc.
   • Turn off the machine power supply.
   • Shut off gas or air supply.
   • Allow the torch to cool before handling or storing.

Safe Operation Guidelines: The following safe procedures and practices help prevent welding injuries and illnesses:

• Always wear appropriate PPE (helmet, gloves, apron): Personal protective equipment helps shield welders from sparks, hot metal, and harmful radiation. A welding helmet protects the eyes and face from UV rays and flying particles. Gloves and aprons made from flame-resistant material guard the hands and body from burns and cuts.
• Ensure proper grounding of equipment: Proper grounding prevents electrical shock by giving electricity a safe path to follow. All welding machines must be connected to a grounded power source, and cables must be checked to ensure there are no breaks or exposed wires.

• Keep workspace free of flammable materials: Sparks from arc welding can easily ignite nearby items. Keeping the area clear of flammable liquids, paper, wood, and cloth lowers the risk of fire. Fire extinguishers must be nearby in case of emergencies.
• Inspect equipment regularly for damage: Damaged cables, torches, or power sources can lead to accidents. Welders must inspect their tools before each job to make sure everything is working safely. Any worn or broken equipment must be repaired or replaced immediately.

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