The savvy seal designer recognizes both the possible uses and inherent limitations of a given product. Though O-rings are ideal for a wide variety of applications, they are not the best solution to every design problem. Since trying to force an O-ring to perform beyond its capabilities can only lead to failure, you will probably be faced from time to time with difficult or unusual situations that require you to consider other seal cross-sections.

What follows is information on a handful of alternate seals that can retrofit directly into standard O-ring glands without the need for either redesign or remachining. Of course, each cross-section has both advantages and disadvantages, so the specific needs of your application will always dictate which one is best for you. Familiarity with your options, however, should make the choice somewhat easier.