B 3.18 X 7.66 X .7/1.4

Back-up Rings have no intended sealing function. Instead, as the name indicates they are supporting elements made with extrusion-resistant materials which generally have a rectangular cross section. They are installed in a groove together with an elastomeric sealing element, preferably with a corresponding O-Ring in static applications. Due to the tight fit of the Back-up Ring in the housing, they prevent extrusion of the pressurized elastomeric sealing element into the sealing gap.

Used in a variety of applications such as with the use of O-Rings in high pressure applications, use of O-Ring materials with a low hardness, compensation of radial sealing gaps, use for internal and external sealing applications, reciprocating and rotating movements possible, compensation for large temperature fluctuations, static and dynamic applications.