WPS, PQR, and Welder Qualification
Welding Procedure Specifications, Procedure Qualification Records, welder performance qualification, and AWS D1.1.
- Explain the purpose and contents of a WPS
- Describe how a PQR qualifies a WPS and a WPQR qualifies a welder
- Identify the scope of AWS D1.1 and D1.2 structural welding codes
Lección 1
WPS Fundamentals
What Is a WPS?
A WPS (Welding Procedure Specification) is a document that provides direction to the welder on how to make a specific weld. It lists the essential variables - the parameters that must be followed during welding. These include the welding process, base metal type and thickness, filler metal classification, preheat temperature, interpass temperature, current type and range, shielding gas, joint design, and welding position.
The WPS is essentially a recipe for making a specific weld. Every qualified welder on a job must follow the applicable WPS.
Essential Variables
Essential variables are the parameters that, if changed beyond specified limits, require a new WPS to be qualified. Common essential variables include:
- Welding process (SMAW, GMAW, etc.)
- Base metal group/grade
- Filler metal classification
- Preheat and interpass temperature
- Position
- Joint design
- Electrical characteristics (current, polarity)
- Shielding gas type and flow rate
Exam Tip
A WPS tells the welder HOW to make the weld. A PQR proves the procedure WORKS. A WPQR proves the welder CAN follow the procedure. Remember this hierarchy.
A WPS is a Welding Procedure Specification that provides the detailed parameters a welder must follow. It is the fundamental document that governs how every weld is made in code-controlled work.