Allowable Leak Rates for Face Seals

[Ussuri]

I have a situation where we have a rubber face seal between a smooth surface and a rough surface. The client has requested we provide a design standard and associated allowable leak rates associated with different types of face seals. Does such a thing exist?

 

[gerhardl]

Different leakrates, and how to measure leakrates exists as several standards (differ for different countries/part of the globe).

It is up to producers to test how good the valve constructions they produce are, tested with/for the different standards.

This includes the different sealing types for the given construction / type/ size / pressure class. No standards that I know of relating different sealing types, only factory internal recommendations for standtime and best choices for different fluids, constrution else equal.

Usually the normalized test is done by drinking water/surrounding temperature.

Suggestion: the customer is perhaps after 'something more' than the usual test, perhaps trying to sava mony or ensure thightness for a given process condition and type of valve sealing.

Try to agree with the customer on what will suit the purpose best as a test at reasonable cost for your company. Perhaps existing procedures with slight variation will do.

Please remember that test done as fresh from production-line product will say nothing about leakage after some time in a pipeline.

Perhaps you can offer some longtime references or tests to prove your product?