What must be detailed in a welding procedure specification (WPS)?

A welding procedure specification (WPS) is a crucial document that outlines the specific requirements for welding procedures. It provides detailed instructions on how welding should be performed, ensuring consistency and safety across operations.

The correct answer highlights that the WPS must include details of the welding process, materials, and equipment. This means that the WPS specifies which welding process will be used (such as SMAW, MIG, TIG, etc.), the type of filler materials, and the equipment necessary for executing the welds. Additionally, it covers important parameters such as preheat and interpass temperatures, welding speeds, and post-weld heat treatment. This comprehensive detail is essential for ensuring the integrity of the weld and compliance with relevant codes and standards.

In the context of the other options, while weather conditions may affect welding operations, they are not a fundamental part of the WPS itself. The certification status of welders is also important but typically covered in other documentation rather than in the WPS. Lastly, cost estimation for welding operations is a financial consideration that does not pertain to the technical specifications needed to perform the welding itself, which is the primary focus of a WPS.