Selection of O-Ring Materials

High thermal resistance and a low compression set are the essential criteria specified for the elastomeric material in demanding applications.

The standard design meets these requirements with the use of nitrile-butadine rubber. For higher thermal stresses, the o-rings are constructed of HNB, SI or VI. The oil compatibility of several elastomers has to be checked. The elastomeric materials listed are offered in various degrees of hardness (Shore) so that the o- ring can adequately perform its function of generating a permanent and consis- tent contact pressure within the sealing system.