WPS, PQR and Welder Qualification Explained
What a Welding Procedure Specification (WPS), Procedure Qualification Record (PQR) and welder qualification are, how they are produced under AWS D1.1, ASME IX and ISO standards.
Saudi Steel Work Editorial Team · · 3 min read
Short answer: A WPS is the written instruction for how to make a weld: process, materials, consumables, joint design, positions, preheat and parameters. A PQR records the test weld and mechanical test results that prove the procedure produces sound welds. Welder qualification tests prove individual welders can make acceptable welds using that procedure.
Clients, consultants and inspectors ask fabricators for WPS, PQR and welder qualification records. Here's what each document is and why it matters.
WPS — Welding Procedure Specification
The recipe for a weld. It specifies:
- Welding process (SMAW, GMAW, FCAW, GTAW, SAW)
- Base metal grade and thickness range
- Filler metal classification
- Joint design and preparation
- Positions
- Preheat and interpass temperatures
- Electrical parameters (current, voltage, travel speed)
- Shielding gas
- Post-weld heat treatment if needed
PQR — Procedure Qualification Record
The evidence. A test coupon is welded following the proposed WPS, then tested (tensile, bend, impact, macro, hardness as required). The PQR records the actual parameters and results. One PQR can support one or more WPSs within code limits.
Welder Performance Qualification (WPQ)
Each welder makes test welds under the WPS, which are inspected and tested. Successful welders are qualified for specific processes, positions, thickness and diameter ranges.
Common codes
| Code | Scope |
|---|---|
| AWS D1.1 | Structural steel welding |
| ASME Section IX | Pressure vessels and piping |
| API 1104 | Pipelines |
| ISO 15614 / ISO 9606 | Procedure and welder qualification (European/international) |
| EN 1090-2 | Execution of steel structures |
What clients should request
- WPS for each joint type on the project
- Supporting PQRs (or confirmation of prequalified status)
- Welder qualification records with continuity logs
- Consumable certificates and storage procedures
Why it matters
Qualified procedures and welders significantly reduce defects, repairs and NDT failures, and are mandatory under most project specifications.
See welding processes, NDT for steel and how to choose a fabrication company.