Final answer:
Changing the filler metal diameter in FCAW Welding requires a WPS Requalification, not a new WPS, to ensure it still meets the necessary standards.
Step-by-step explanation:
If you want to change the FCAW (Flux Cored Arc Welding) filler metal diameter to the next size up, then you would require a WPS Requalification. The reason being that changing the diameter of the filler metal is related to the welding procedure specification and can significantly alter the way a weldment is constructed or function. Therefore, you would need to requalify your WPS (Welding Procedure Specification). This would ensure that your new welding procedure using a different filler metal diameter still meets the requirements of the applicable code or standard.
Learn more about Welding Procedure Specification