Gasket Thickness for Large Tongue and Groove Flange

[onrush]

Dear members,

In process piping area, we normally specifies 4.5 mm Th'k for spiral-wound with graphite-filled gaskets and 1.6 or 2 mm for sheet gaskets to be used for FF or RF flanges connections.

However, when we use the large tongue and groove flanges with metal gaskets, what is the normal practice of the gasket thickness?

Always thanks....

 

[Cockroach]

The same. I've never differentiated between the two cases since they must provide a positive seal. Typically I steer away from the 4.5 mm Spiral Wound ones because of the crushing thickness giving more of a standoff between the tongue and recess depth. Go with the 2 mm version and use the rated stud/nut torque specifications.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada