Determine whether a welder needs ASME Section IX qualification or AWS D1.1 qualification for a job welding structural steel connections on a pressure vessel skid

Steps

1. Identify what the weld actually joins: structural framing/buildings/bridges falls under AWS D1.1; pressure-retaining vessels, boilers, and piping fall under ASME Section IX (referenced by BPVC and B31 piping codes)
2. Check the governing contract or code of construction specified by the engineer of record or owner, since scope is set by the applicable code, not by the shop's preference
3. Note that ASME IX qualification is process/procedure-and-performance based (WPS+PQR+WPQ) covering a very broad range of materials and processes, while D1.1 is a self-contained structural code with its own prequalified WPS provisions
4. Confirm a welder qualified only under D1.1 is not automatically qualified under ASME IX and vice versa; requalification testing is required to cross over
5. Escalate to the certifying engineer or AWS/ASME help desk if a single fabrication spans both scopes (e.g., a vessel skid with structural supports), since mixed-scope jobs may require dual qualification
6. Do not assume equivalence of position or process variables between the two codes even where terminology overlaps (e.g., 2G/3G/4G positions)