O-rings

O-rings and back-up rings

O-rings are one of the most common sealing solutions. SKF supplies O-rings in a wide range of sizes and materials, making them suitable for a wide variety of operating conditions and applications. They are easy to install and enable simple, cost-effective seal housing designs.

O-rings maintain sealing contact force through radial or axial deformation in the seal housing between two machine components. The most important criteria affecting the maximum operating pressure at which O-rings can be used for static radial sealing are:

• extrusion gap
• material
• sealed fluid
• temperature

Under certain conditions there is a risk of gap extrusion. Back-up rings prevent O-ring extrusion in static radial sealing applications.

O-rings are used in a wide variety of applications sealing different media. This section focuses on hydraulic cylinder sealing systems. Therefore, this section and the recommendations provided apply to static sealing of conventional mineral-based hydraulic fluids.