Just realized a trick for getting a stubborn flange to seat on a boiler feed line

Last month I was fighting a 4-inch flange that just would not line up right, even with new gaskets. Out of ideas, I heated just the flange itself with a torch for about 30 seconds, not the pipe, and it expanded enough to drop right into place. Let it cool and it sealed up tight with no leaks. Has anyone else tried using heat like that on a tricky fit, or do you have a different go-to method?

4 comments

4 Comments

jamie8041mo ago

Read something similar on a plumbing forum a while back where a guy swore by a quick heat cycle on the flange, not the pipe. Said it worked best on cast iron fittings that were just a hair too tight. I'd still be careful around any old pipe or a flange that looks brittle, since sudden heat can crack it.

the_terry2mo ago

Heating just the flange is a solid trick for a tight fit. You do want to be careful not to overheat it and warp the metal, though. A little heat goes a long way.

logan5612mo ago

My old shop teacher swore by a propane torch for stubborn flanges. You just need to heat it evenly in a circle, not one spot. It works if you know what you're doing.

terry8352mo ago

Whoa, hold on, heating a flange like that sounds like a great way to cause a leak down the road! You're putting stress into that metal that wasn't there before. My go-to is always a proper alignment pin or even just a bigger pry bar. Forcing it with heat just seems like asking for trouble when it cools and contracts again.