Why does nobody talk about how easy it is to screw up a flange fit-up?

I was on a job last month down in Houston, and this guy kept fighting with his flange alignment for almost an hour. I walked over and noticed he had the gasket pinched on one side because the studs were tight on the other side first. I loosen everything up, center the gasket proper, and tighten in a star pattern instead of going around in a circle. Took maybe 10 minutes total after that. Has anyone else seen people just crank down in sequence instead of doing it right?

2 comments

2 Comments

rowan6662d agoTop Commenter

Funny you mention that star pattern thing, but actually the star pattern isn't always the best call for flanges. For most standard flanges, you're supposed to go in a cross pattern, not a star, especially if it's a raised face flange with a spiral wound gasket. A star pattern might work on some small stuff, but on bigger flanges with thicker gaskets, you'll get uneven compression and end up with the same problem you're trying to fix. That guy you helped probably just needed to start snug on all bolts, then go around in 180 degree increments a few times. It's one of those things where the theory sounds right but the hands-on reality is a little different.

hunt.rowan2d ago

Had a 24 inch flange blow on me once because someone did a star pattern on a spiral wound gasket...