How To Estimate Hydrodynamic Seal Leaks?

[byrdo]

I am trying to estimate the amount of HC's that leaks out of a hydrodynamic seal on a large gas compressor. The seal has two sealing faces and two buffer gas purges, JC Type 28AT. It is assumed that both the primary and secondary faces failed and opened completely. How should the environmental release be estimated?

 

[smckennz]

Just as you would think.
If the seals have failed, then you must discount them. You need to look at the three entry areas and pressures, and the combined exit area and pressure. It is most likely that the purge supplies cannot keep up with the leakage flows and can possibly be ignored.
A series of choked flow orificies is probably a good way to start this exercise.

Cheers

Steve McKenzie

 

[longeron]

Byrdo

If both faces opened completely, then each seal acts like a bushing. So with this 28AT, 2 bushings for the faces plus a secondary containment or segmented bushing for the second buffer gas purge (1 purge between the two sets of seals).

If you still have the seal parts you may want to call in your seal rep to perform a failure analysis.