The issue of leakage on failure is usually addressed by a close clearance floating carbon bushing located on the atmospheric side of the seal. The space between the bushing and the seal is purged with low pressure (2-3 Psi) dry steam. The steam has two functions, 1) to prevent oxidation of the...
You should switch from your double seal to a single high temperature metal bellows seal. The problem with plan 54 is that it is susceptible to flow or pressure interruption from a variety of causes. I assume you are flushing with a cooler gas oil stream which is OK if the operator controls it...
your problem is common when handling latex based media. The comment you found is probably a good enough explanation of the failure mode. The latex is shear sensitive and since, in a single seal application, the media forms the lubricating film between stationary and rotary faces the latex...
the best mechanical seal "textbook" I have read is Mechanical Seal Practice for Improved performance published by Mechanical Engineering Publications for The Institution of Mech. Engs in London.(ISBN 0 85298 806 0)
Burgmann also have a great mechanical seal dictionary full of good...
