Failure Without Visible Evidence on Seal

Failure Pattern: Of the various types of seal failure, this is among the hardest to diagnose because the result of the problem is not visible on the O-ring.

Problem Sources: Lack of compression...Tolerance stack-up...Eccentric components... Parting lines/flash... Improper seal/gland volume relationship.

Suggested Solutions: Maintain recommended compression range for the application... Identify the amount of stretch as it reduces the O-ring cross section with increased stretch... Determine the component tolerance stack-up as it directly affects the seal cross section... Consider maximum component shift in design to ensure that compression is still contained within recommended compression range... Avoid parting lines in O-ring grooves as they tend to be areas of flash and mismatch... Ensure that the O-ring gland volume surpasses the O-ring volume to allow for seal expansion without seal detriment.