Steam Pipe Insulation per Code Requirements

PaulVW

In 1 of the cities I service, the city is requiring all new pipes on replacement steam boilers to be insulated even if none of the other pipes are insulated. I understand the value of insulating steam pipes but I believe I read or heard in one of the Don H seminars that it was a bad idea to insulate the wet return on a 1-pipe steam system. As I remember the condensate needs to lose some heat before it gets to the close nipple of the Hartford loop to reduce flash steam and banging. I looked through “Lost Art of Steam” and could not find it. (I do need to buy a new book, it was bought in 1993 and is quite worn...) Please let me know if I’m on the right track, I have to document it for the inspector.

Jamie Hall

The condensate in the wet returns should not be that hot in the first place -- one pipe or two pipe. Further, the pressure at the Hartford loop -- applied by the equalizer -- should be high enough to prevent any possibility of flashing.

In my opinion and understanding, anyway...

DanHolohan

Paul, I believe condensate returns and better off insulated. As water cools, it absorbs carbon dioxide, which results in carbonic acid that rots pipes.

ChrisJ

My wet return runs much hotter now that I insulated the dry returns especially when it's very cold out. Not sure how hot, but too hot to touch.

I wish I could insulate the wet return, but it's placement makes it kind of difficult if not impossible.