Back Up Washers are used in conjunction with ‘O’ Rings for both static and dynamic sealing applications. The prevent extrusion of the ‘O’ Ring when it is subjected to high pressures, or when the extrusion gaps are excessive.
Whenever possible two Back Up Washers should be used, one on each side of the ‘O’ Ring.
All Series 19 Back Up Washers are continuous one piece rings, so they will not pinch ‘O’ Rings. The Polyurethane material used, allows the rings to be stretched over pistons for easy installation.