Welding and Hot Work Procedure

Purpose. Describes the mandatory steps for setting up, performing and finishing welding, thermal cutting, heating and gouging safely and to the required quality at any Nexus site.

1.Scope

This procedure applies to gas metal arc, gas tungsten arc and manual metal arc welding, oxy fuel and plasma cutting, heating and gouging in the fabrication shop, assembly hall and any other area. Hot work outside the designated welding bays requires a hot work permit issued by the supervisor.

2.Qualification

Only welders who hold a current welder qualification for the process, position and material recorded in the training records will weld structural members. Apprentices must weld under the direct supervision of a qualified welder until signed off. Welding procedure specifications for each joint type are held at the bay and must be followed.

3.Set up

Check the drawing revision and the weld symbols before starting. Confirm the welding procedure specification for the joint, set the machine parameters, check the gas supply, the earth clamp and the leads for damage. Position the local exhaust ventilation hood within the capture distance of the arc. Clear combustibles for ten metres or shield them, and confirm a fire extinguisher is at the bay.

• Drawing revision confirmed
• Welding procedure specification at hand
• Leads, clamp and torch inspected
• Extraction positioned and running
• Combustibles cleared or shielded
• Extinguisher at the bay

4.Personal protective equipment

Wear a welding helmet with the correct shade, flame resistant clothing with sleeves down, leather gloves, safety boots and hearing protection. Use a powered air purifying respirator for stainless steel, galvanised material and any welding in a confined area. Screens must be placed to protect other workers from arc radiation.

5.Welding and inspection

Tack, check dimensions in the jig, and weld in the sequence on the specification to control distortion. Remove slag and spatter and visually inspect each weld for profile, undercut, porosity and cracks before presenting the assembly for the fabrication gate inspection. Record the welder identification and the procedure used on the work order.

6.Finishing hot work

Switch off the machine, close gas cylinders and bleed the lines at the end of the shift. Inspect the area for smouldering material and maintain a fire watch for thirty minutes after any hot work outside a bay. Return the hot work permit to the supervisor with the fire watch signed off.