The proper amount of 'Squeeze,' or the relationship between the O-ring cross section and the hardware grooves, is best designed in consultation with a Gallagher engineer.
Typical elastomeric materials available are Silicone, FKM and EPDM. More exotic elastomers would require an RFQ to a Gallagher Engineer.
FEP or PFA encapsulated O-Rings have tremendous chemical and temperature resistance.
PFA or FEP encapsulated O-Rings offer tremendous chemical and temperature compatibility compared to their elastomeric counterparts. While high levels of temperature and chemical resistance exist for purely elastomeric O-rings, this performance comes at a premium cost. Depending on the application, an FEP or PFA O-ring may perform at levels consistent with a Perfluoroelastomeric O-ring.
Drawbacks to encapsulated O-rings are reduced sealing performance at low temperatures, and the lack of performance in dynamic applications. Also, because most encapsulated O-rings are extruded and spliced, the quality of the bond can have significant impact on their performance.
Mouse over the above images to learn more about these products. Consult a Gallagher Engineer with specific application questions.