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

A WPS is a documented procedure specifying how welding should be performed for a specific application. It includes: Joint design and dimensions, Base metal specifications, Filler metal requirements, Preheat and interpass temperatures, Welding parameters (current, voltage, travel speed), Position and progression, Shielding gas composition, and Post-weld heat treatment. WPS ensures consistent weld quality, is required by codes (AWS, ASME), must be qualified through Procedure Qualification Records (PQR), and is essential for traceability and quality assurance in critical applications.