Indications: Blisters, cracks, voids or discoloration.
Contributing Factors: Incompatibility with the chemical and/or thermal environment.
Indications: Small cuts, nicks or gashes
Contributing Factors: Sharp edges on glands or components. Improper sizing of elastomer. Low-modulus / hardness elastomer. Elastomer surface contamination.
Indications: Foreign material on the surface or within the cross section
Contributing Factors: Process environment deposition. Reactions or degradation of the elastomer.
Indications: Flat-sided cross section corresponding to mating seal surfaces
Contributing Factors: Excessive compression. Excessive temperature. Incompletely cured elastomer. Elastomer with high compression set. Excessive volume swell in chemical.
Indications: Surface blisters, pits or pocks. Absorption of gas at high pressure and subsequent rapid decrease in pressure; elastomer surface blisters and ruptures as pressure is rapidly removed.
Contributing Factors: Rapid pressure changes. Low-modulus/ hardness elastomer.
Indications: Often difficult to visually detect; may exhibit a decrease in cross-sectional size
Contributing Factors: Improper or improperly cured elastomer. High vacuum levels. Low hardness/ plasticized elastomer.