i make most of my manifolds with mild steel flanges and schedule 10 304ss pipe. on this particular manifold the customer wanted stainless.

i'm curious of everyone's experience with welding the inside of the flange to pipe joints like on the head flanges and collectors etc.

i've always welded the inside of the joints and not had any problems. i've seen lots of other manifolds without any welding on the inside but don't know if there has been a problem as a result.