Switched from a standard 3/8-inch gap to a 1/4-inch on our tube sheet layout and the weld quality is way better.

We were working on a heat exchanger for a plant in Toledo and kept getting too much heat distortion on the tube joints. My foreman suggested we tighten the gap from the usual 3/8-inch down to 1/4-inch. After trying it on the next unit, the welds are cleaner and the fit-up is way easier to manage. Anyone else have a go-to gap size for different pressure vessel work?

4 comments

4 Comments

gavinwells2mo ago

Disagree, that gap change could cause stress cracking later.

clairen852mo ago

Huh, never considered how that gap might affect heat flow.

rubyshah2mo ago

Right, @clairen85? It's the secret heat escape route. My house runs on that principle.

ivanross2mo ago

Oh man, that reminds me of a buddy who sealed up all the drafts in his old place. He was so proud until summer hit and his attic turned into an oven. Turns out that one vent he missed was actually letting all the hot air out. He had to go back and open a few things up on purpose. Sometimes those gaps are doing more work than we know.