General technical information

Designing sealing and guide systems in hydraulic cylinders requires careful attention to the interaction between all cylinder components and the operating conditions as well as the application requirements. Sealing systems are important because they keep the fluid media and the system operating pressure in and contaminants out of the cylinder. Guide rings provide effective guidance of components that are in relative motion to each other and accommodate radial loads acting on the cylinder assembly. The selection of the right seal and guide for a given application requires consideration of many factors. Therefore, SKF manufactures and sells hydraulic seals and guides in many different profiles, materials and in a wide range of series and sizes, which make them appropriate for a wide variety of operating conditions and applications. Each of these designs and material combinations has specific properties, making them suitable for a particular application.
This section and its sub-sections provide the necessary basic information. It starts with an overview over hydraulic cylinder types and classification, and an introduction to seal and guides with their functions. Furthermore, technical information such as seal countersurface finish properties, materials, fluid media and gap extrusion are discussed in detail. Product storage and installation is included as well. The seal type sections provide type and profile specific information and characteristics are discussed in detail too.
Obviously, it is impossible to include all the information needed to cover every conceivable application. If application requirements are not served by the common profiles or sizes in these sections, contact SKF for additional information and for providing a specific offer. For any application factors outside of the ordinary, or to specify sealing systems in new hydraulic cylinder designs, a certain amount of expertise, beyond the content of this section, may be required. The hydraulic seal experts at SKF can assist in selecting the right sealing system for new cylinder designs.

Colour coding for material

The product illustrations in the following sections use a colour coding system to indicate the material group (table 1), but they do not match the actual material colours. For information about the actual material colours, refer to Materials.
SKF logo