Extrusion Resistance

Extrusion occurs when system pressure forces the seal from its groove and into the clearance gap with-in the seal housing. Proper groove dimensions and seal selection combined with elastomers designed to resist extrusion can prevent this type of failure. The potential for extrusion to occur is greater with a larger gap.  O-rings are tested under differential pressure at temperatures up to 300°C to quantify extrusion resistance. Short-term (30 minute), long-term (days), and cyclic-pressure extrusion tests can be run.

Extrusion pressure is dependent upon many factors but a constant set of gland dimensions are established to compare extrusion properties of materials. Both rubber O-rings and plastic V-rings can be tested are shown below as an example.