Welding Processes and Procedure Qualification
Welding processes tested include SMAW, GMAW, FCAW, and SAW. The exam expects you to separate three documents: the WPS (written instruction), the PQR (record of procedure qualification testing), and the welder performance qualification (personnel). A prequalified WPS still must be written and followed; prequalification removes the need for procedure qualification testing only when all code conditions are met.
Essential variables
- Process and transfer mode.
- Filler metal classification.
- Base-metal thickness and group.
- Joint design and backing.
- Position and progression.
- Preheat, interpass temperature, and heat input.
Worked example
A shop has a PQR for SMAW E7018, 12 mm plate, flat position. A job calls for 25 mm FCAW, vertical uphill. Do not “adapt” the old WPS. Process, filler, thickness, and position are essential variables outside the qualified ranges, so a new WPS and supporting PQR are needed. Reasoning: the PQR proves only the tested combination; it is not a universal approval.
Traps
- Filing the PQR where the WPS should be.
- Calling a WPS “prequalified” without checking joint details, filler, and thickness limits.
- Ignoring heat-input limits on higher-strength steel.
- Confusing procedure qualification with welder qualification.
- Missing revision control or supporting test records.