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o-ring size selection?

o-ring size selection?

o-ring size selection?

Hi. I have a port on a pressure vessel (14 bar). The port is 2" diameter hole. A flange plate bolts over the port. The fasteners are on a 5" PCD. I need an o-ring to seal the port. Should I select an o-ring size that is close to the port size, i.e. just over 2". Or, should I select an o-ring that is close to the fastener PCD, i.e. just less than 5"?

With the former I will be minimise the surface area that is under pressure. With the latter I'll be ensuring good clamping on the o-ring.


RE: o-ring size selection?

Any thoughts on this one anyone?

RE: o-ring size selection?

I've always gone with the minimum area approach, and size the bolt circle appropriately. A hand calc stress analysis, or FEA, will help predict if the flange is too soft and allow a gap to open for the o-ring to extrude through.

RE: o-ring size selection?

The smaller the seal ID the better. Less pressure load therefore everything else can be down sized, less expensive. I like to keep cross section up when possible. Small cross sections make it much harder to control the squeeze.


The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

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