Minnesota Rubber pioneered the design and production of four-lobed seals with the patented QUAD-RING® design. These seals are used today around the world for a wide variety of static and dynamic sealing applications.

The four-lobed design provides twice the sealing surface of a comparable standard o-ring and because of this double-seal action, less squeeze is required to maintain an effective seal. This reduction in squeeze means less friction and therefore, improved seal life.

Unlike o-rings, where parting lines are on the sealing surface, QUAD-RING® seals' parting lines lie between the lobes, away from the sealing surface. This design eliminates the problems of leakage often resulting from a parting line's irregular surface.

QUAD-RING® seals can be used as compression-type seals in high speed rotary applications, eliminating the need for costlier spring-loaded seals. They offer low friction for long life in hydraulic systems with speeds of up to 900 FPM (4.5 M/Sec).

Avoiding Spiral Twist

In order to minimize breakaway friction, an o-ring groove must be wide enough to allow rolling or twisting of the seal. In the long stroke of a reciprocating seal application, this twisting action can strain and finally rupture the rubber, resulting in a type of seal failure known as spiral twist

The QUAD-RING® seal's four-lobed configuration is designed to withstand the distortion and extrusion often caused by high or pulsating pressure, and thus eliminates this rolling action. As a result, a QUAD-RING® seal calls for a narrower groove cross-section than does a comparable o-ring seal. The following sections are guidelines for the design of QUAD-RING® seal grooves for both rotary and non-rotary applications.