Ring type Gaskets

[sureshchoksi]

Can some one clarify on the interchangeability of Oval Ring type Gasket with Octagonal Ring type gasket? To be very specific, as I understand,
A. Flange with Octagonal Ring Groove: Oval Ring or Octagonal Ring type Gasket can be used.
B. Flange with Oval Ring Groove: Can Octagonal Ring type Gasket be used for Oval Ring Groove Flange, or only Oval Ring type Gasket can be used? Thanks.

 

[Krausen]

A. Correct
B. Only an Oval Ring type gasket can be used with Oval groove RTJ flanges

 

[sureshchoksi]

Thank you very much Krausen for your valuable feedback strengthening my view.

 

[LittleInch]

Are these very old flanges? As far as I can see, no one makes Oval shaped ring joint flanges and they all became flat bottomed about 1960?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[sureshchoksi]

These are the flanges of Heat Exchanger Nozzle, and its some how recent one. Not old one.