Tongue and Groove Flanges | Eng-Tips

Our customer is builing a 6' diameter vessel, 600 psi @ F. Initially, the vessel was specified with raised face
body flanges. After futher review the cusomer is interested in using tongue & groove flanges.

Is ther any guidlines for when a raised face joint won't work and a T & G flange is neded. We normally go with RTJ flanges when we are concerned there could be problems with a RF flange.
We stay away from T&G flanges especially if they will there be frequent making and breaking due to potential damage to the tongue. Also some T&G gaskets are quite fragile.

We don't have any trouble with RF flanges as we used the appropriate spiral wound gaskets and kinda insist on proper make up using new gaskets each time.

What was the clients specific concerns? Ohio Bob...

In response to your question, no... there are no hard and fast rules about flange face selection and yes... there is overlap in acceptable pressure ranges

I would suggest that you stay with the RF flanges mostly for the reasons stated above. In my opinion, only when you have exceeded the design condition of ASME Class 900 for the flanges should you consider someting other than RF.

-MJC