Flange Finsh 3

[Chris0164]

Hi Guys,

Just being bussy specifying the flange finish for and ANSI B16.5 raised face flange for a ejector mixer. We are using graphite envelope gaskets with stainless steel insert. I can specify serrated spiral or concentric grooves in the raised face surface. Which type of grooves do I speciffy when ??

Thanks for any reply

Chris0164

Kind Regard,

Chris

 

[SnTMan]

Chris0164, why don't you just let the finish in ASME B16.5 (not ANSI any longer) govern? Spiral grooves would be preferred I would expect.

Regards,

Mike

 

[jte]

I agree with the B16.5 approach (paragraphs 6.4.5.x). But in my experience, concentric grooves are preferred, the argument being that spiral grooves provide a leak path. Can't say that I completely buy the argument, but haven't found a reason to get excited about it.

jt

 

[Tmoose]

IF the clamping pressure is high enough to force the gasket material to conform, and IF the flanges are thick enough, and IF he bolt spacing is tight enough, then a spiral groove on the flange face whose dimensions don't violate the surface finish specs, won't allow a leak.

Similarly, at least in my mind, Most lip seal manufacturers specify a plunge ground sealing surface (creating pure circumferential grooves, not helixes) in addition to a surface finish when leaks must be minimized.