Weld build up of buttwelded valves

[carlo1023]

Is it possible to apply weld build up to valves to reach a higher schedule? For example, you have a buttweld valve with a lower schedule but you need a buttweld valve with a higher schedule, can weld build up be applied to reach the requirement?

 

[MTPipeliner]

Physically, yes it's probably possible. I would say that it's not a good idea, and that it likely voids waranties, is out of spec, and is not in compliance with codes.

 

[reverman]

Yes. Valve modifications shops (and OEMS) do this all the time. As long as your using qualified section IX welders and weld procedures this will not be a problem. It will likely void the warranty unless you go back and confirm it with the original manufacture.