Four years of welding experience, OR, Completion of an accredited four year welder’s training program: OR, Completion of an accredited two year welder’s training program and two years of welding experience: OR, Any equivalent combination of experience and/or education from which comparable knowledge, skills, and abilities have been achieved. Control the processes of fitting, burning and welding to avoid problems in relation to overheat, distortion, expansion or shrink of spare parts.