NBR,viton,Epdm,silicone, Neoprene,HNBR, encapsulated O-rings and etc. are available

o-rings for mechanical seals: rubber bellows for mechanical seals
NBR,viton,epdm,HNR and Neoprene,aflas and kalrez are available and PTFE is used as a wedge or a gasket or a bellow.Encapsulated o-rings are also available

self-energizing o-rings do not require much mechanical preloading which allows O-rings to be used at very high pressures and are offered in a complete range of chemical resistant and general working conditions. NBR, Neoprene,EPDM, Viton, and Kalrez are typical materials selected for a variety of service conditions. Teflon is not a good material for an O-ring, particularly when the it is to be dynamic. The encapsulated O-rings.are utilized to gain the chemical resistance offered by Teflon . The encapsulated “O” ring is sensitive to temperature fluctuations so encapsulated O-rings are usually recommended only for static sealing elements