P.T.F.E or P.T.F.E. with filled grades such Bronze, Glass, Graphite
Material :
Backup Rings are used in conjunction with O-ring for both static and dynamic sealing applications. They prevent extrusion of the O-ring when it is subjected to high pressures, or when the extrusion gaps are excessive. Wherever possible two Back-up rings should be used, one on each side of the O-ring.
Back - Up - Ring.......