Use of O-Rings

These seals are used in two general design applications: static and dynamic. Static applications may range from vacuum to over 60,000 psi for sealing flanges and O-ring grooves. Oring seals with lobed cross sections were designed for both static and dynamic applications. The four and six lobed configurations resist spiral failure and also extrusion failure in applications with large clearance between parts.

Of the some 20 different types of o-ring seals available, the common O-ring type is the most versatile. The conventional type of Oring may be used in almost any application if the gland to contain the seal is designed correctly and the right size and material is chosen for the O-Ring.


Back-up Washers

Back-up washers are used in conjunction with o-rings 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 washers should be used.

Types of Back-up Washers

For general use, for example either for rod or piston.
For rod applications with interference fit on O.D.
For piston application with interference fit on I.D.