Anti-Extrusion Rings

since 1977

Production of Anti-Extrusion Rings

Anti-extrusion rings (also known as back-up rings or simply BK) are used in conjunction with O-rings in both static and dynamic applications. For static seals, pressures of up to 400 bar are allowed, while for dynamic seals, pressures can reach up to 350 bar.

Their Function

Anti-Extrusion Rings

Their main function is to prevent the extrusion of O-rings into the gap between metallic components. The use of anti-extrusion rings becomes necessary when conditions such as high pressures (usually above 100 bar), significant clearances, high fluid temperature, a large number of cycles, high movement speed, significant temperature or pressure variations, and the presence of contaminated fluids are present during operation.

Pressure

We work with all types of thermoplastic materials

If the pressure acts from only one side of the O-ring, it is sufficient to install a single anti-extrusion ring on the opposite side to the direction of the pressure. However, if the pressure acts on both sides of the O-ring or if the fluid is contaminated, it is necessary to install two anti-extrusion rings, one on each side of the O-ring.

There are various types of anti-extrusion rings, depending on the specific requirements of each application.

The most commonly used material for the production of anti-extrusion rings is PTFE (virgin or loaded with carbon graphite or bronze). For special applications, materials such as polyamides (PA 6, PA 12, DEVLON), PEEK, POM, PCTFE, and PE may be required.