ASME BPVC Section IX
Welding, brazing and fusing qualifications
The American route, and the code most often specified on work outside the European Union — dominant in North America and the Gulf. Procedure and performance qualification through essential, supplementary essential and nonessential variables.
What it governs
Section IX of the ASME Boiler and Pressure Vessel Code sets the rules for qualifying welding procedures and the people who follow them. It is referenced by the construction codes — Section VIII for pressure vessels, B31.3 for process piping, and others — which say what to build; Section IX says how the welding is qualified.
The variable system
Everything turns on variables. For each process, the code lists:
- Essential variables — change one and the procedure must be requalified
- Supplementary essential variables — additional ones that apply when notch toughness testing is required
- Nonessential variables — can be changed with a revision to the WPS, without requalification
Performance qualification for welders has its own, shorter list. This is why the same physical change can be trivial in one context and disqualifying in another, and why the distinction is worth having a machine keep track of.
Groupings
P-numbers group parent materials, F-numbers group filler metals by usability, and A-numbers group weld metal by chemistry. A qualification made on one member of a group generally extends across it — with exceptions that are the reason people get this wrong from memory.
Continuity
A welder’s qualification remains in effect provided they have used the process within the preceding six months. Lapse it and requalification for that process is required. The record that proves continuity is production work — which means it only exists if production work was recorded against the welder in the first place.
What has to be recordable
- The WPS, its supporting PQR, and the construction code it was written against
- The qualified ranges derived from the PQR values, not transcribed
- Welder performance qualifications and their ranges
- Six-month continuity evidence per welder per process
- Revisions, and which joints were welded under which revision
Where the European and American routes part company
Under PED, for categories II and above the joining procedures and welders must be approved by a notified body or a recognised third-party organisation. Under ASME, qualification is normally the manufacturer’s own responsibility, audited through the certification programme. A shop working both markets runs both models at once, on the same welders — and Worgify keeps the ASME and PED records on those welders in one place, so continuity, procedures and approvals reconcile automatically rather than by hand.
Where it's used in Worgify
This standard is wired into these parts of the product — not just described here.