Gasket Oversized

[wreg]

Hi Gents,
I'd like to know what can happen if I install a oversized gasket (AISI 316) between body and bonnet of a gate valve (F6NM). Any consideration will be appreciated

Wreg

 

[Hush]

What do you mean by oversized?
If its a different diameter it probably won't seal.
If its a different height it may not drift, unless its reverse acting, in which case the vbsm may not seal.

 

[wreg]

I'm speaking about conical gasket with the external diameter oversized. I want to do this to well energize the gasket but I'm not sure that this will solve my problem. Have you any experience on this?

 

[Hush]

Assuming you have a face to face makeup between the body and bonnet the result would be increased bolting stresses and an increase in stress in the hub of the bonnet. As long as the increase in size is 'slight' the increased stresses shouldn't be enough to worry about.