Depending on the ambient and operating temperature of the face seal, the O-rings or trapezoidal rings can be made from a choice of four proven basic elastomeric materials in different grades.Each elastomeric material is highly resilient and will show very little permanent set which ensures a reliable static seal and clamping action.
NBR – standard
HNBR – higher temperatures
VMQ(silicone rubber) – covers temperature in both hot and cold extremes
FPM(Fluorine rubber) – extends the maximum temperature while offering excellent oil compatibility