A mechanical test that is performed by pressurizing an O-ring (or Backup Ring) in a gland with a specific squeeze and extrusion gap at a specific temperature.  The pressure is applied at a constant rate to determine the extrusion initiation pressure and final failure pressure of the tested specimen.  This test is best used as a comparative tool for perspective compounds.  Alpine Polytech can also use ASTM D395 Type 1 compression set specimens to test extrusion resistance.

Keywords: Initiation Pressure, Failure Pressure, Extrusion