When an O-ring is under high-pressure gas for an extended period of time, and that pressure is reduced too rapidly, explosive decompression can occur. The gas that gets trapped or absorbed in the O-ring’s micropores causes splits or ruptures in the surface of the O-ring.

Hardening and oxidation occur when the part is exposed to high temperatures for an extended period of time, causing plasticizer volatilization and oxidative cracking. As the O-ring material hardens, the O-ring is unable to retain sealability, causing leakage and failure to occur.

While O-ring designs are meant to withstand outside influences within the application environment in which they are used, failure is still possible. A combination of factors, from design to human error, can contribute to the premature failure of an O-ring.

In this edition, we’ll discuss the causes and signs of extrusion damage, as well as potential solutions and methods for prevention. Extrusion damage failures often occur in dynamic applications such as hydraulic controlled rod and piston seals. These can also occur in static applications when seals are subjected to high-pressure pulsing, especially when the gland extrusion gaps are excessive.