Choosing a Rubber Compound for High Temperature Gasket Applications
There are several rubber gasket compounds for use in elevated temperature applications. There are, as usual, many things to evaluate before selecting the proper material.
Besides the temperature range, the fluid (or media), system pressure, and exposure conditions need to be considered. Those factors will affect the final choice, but this brief overview will highlight temperature limits.
For applications where the rubber material will not be exposed to acids, alkalis, superheated steam (over 250ºF), aromatic hydrocarbons, and certain fuels, Silicone is a good choice for the gasket you will using. Silicone has a superior temperature range, generally remaining flexible from -75ºF to + 450ºF, and is the compound of choice for hot, dry air gasket applications.
Viton®, while not a very good compound for low temperatures, is an excellent choice in high temperature gasket applications up to approximately 400ºF. Viton® has superior resistance to a wide variety of chemicals, including many acids, fuels, aromatic hydrocarbons, chlorinated hydrocarbons, and non-flammable hydraulic fluids. All of the Viton® gaskets we supply are made from genuine DuPont material; not a generic FKM.
EPDM is the best rubber gasket material for steam and hot water applications to 350ºF, with some EPDM materials capable of handling temperatures in steam to 400ºF. EPDM is not compatible with petroleum based fluids, but can handle many Glycol based fluids to 300ºF.
Perfluoroelastomers handle a wider range of chemicals than Viton®, but most commonly are available only as O-rings. Perfluoroelastomers (the most commonly known is Kalrez®) generally are heat resistant to 600ºF, but due to their extreme expense, and limited shape and size availability, should be considered only when the application cannot be sealed with another material.
When temperatures exceed the limits noted above, it is likely a material other than rubber will be needed.
Please contact Expert Gasket & Seal for additional assistance with your application.