By Ken Fields, CET, CWI

Welding Procedure Specifications (WPS) are the parameters and variables a welder must follow to consistently produce sound welds. In the profession, WPS can also go by Preliminary WPS, prequalified WPS, Standard WPS, or simply a WPS. In the end, Welding Procedure Specifications are simply Welding Procedure Specifications. Below is a brief description of the four types of specifications and how they come into play when developing the end product—otherwise known as a qualified WPS—after completing all the required testing.