What is a Welding Procedure Specification (WPS) and why is it essential?

• A. A warranty certificate
• B. A documented welding procedure with parameters; ensures repeatable, code-compliant welds
• C. A permit to perform hot work
• D. A list of allowed welders

Answer: (B)

A Welding Procedure Specification defines exactly how a weld should be made and why it matters. It lays out the welding process, materials, joint type, thickness, and all the parameters that control the weld—filler metal, shielding gas, preheat, interpass temperatures, post-weld heat treatment, welding position, and acceptance criteria. By documenting these details, the WPS ensures every weld of a given type is produced the same way, which leads to consistent strength, toughness, and corrosion resistance, and it provides traceability to meet code and project requirements.

This isn’t a warranty certificate, which is about guaranteeing a product after the fact. It isn’t a permit to perform hot work, which is a safety authorization for ignition hazards. It isn’t merely a list of allowed welders, which concerns who can weld rather than how to weld. The WPS focuses on the method itself, making repeatable, code-compliant welds possible across different operators and materials.