I have a situation where an existing 16" ASTM 53 pipe needs to reduce from the 16" diameter to 12" and back to 16" in about 30" horizontal distance. The connection point is an existing 16" WNF, then need to install a 12" plug valve with a PLIDCO flange...
I have a contractor submitting WPQ for his welders dated 1994,'97,'98,and '99. Spec is b31.3 gmaw for astm a53 pipe line work. I think this is to old a WPQ and I should request new. Any industry guidelines, Thanks