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Buna-N
This compound has excellent resistance to petroleum oils and gasoline and has good resistance to hydrocarbons, acids and bases. Buna-N has a temperature range of -40ºF to +250ºF and has excellent resistance to compression set. Durometers available are 70 (standard) and 90. Silicone
Silicone
"O" rings resist compression set and retain good elastomeric properties at both low and high temperatures. They have a temperature range of -100ºF to +500ºF. Silicone has good resistance to solvents, fuels and many chemicals. Durometers available are 50 (standard) and 70.
Viton®
"O" rings have excellent high temperature capability with resistance to a wide range of acids, hydrocarbons and chemicals. Viton® is one of the only synthetic rubber compounds that resists chemicals such as Benzine, Toluene and Trichloroethylene to name a few. Durometers available are 70 and 90.
Other Materials
PTFE
EPDM
Butyl
FDA (Viton® Buna-N or EPDM)
Kalrez®