If my procedure was ran using a St/st 316L pipe to an API5L Grade B pipe both 3" Sch 40 will this cover my procedure to weld fittings 316 to Carbon Steel. Can anybody point me in the right direction . Cheers
It depends on the Code you're working with, but ASME IX would permit what you've described as long as the P-Number or S-Number of the carbon steel is the same as the API 5L Gr B material.