Hydraulic seals are generally relatively soft, non-metallic rings captured in groove or fixed in a combination of rings, forming a seal assembly, to block or separate fluid in reciprocating motion applications. They can be made from a variety of materials such as polyurethane, rubber or PTFE. The type of material is determined by the specific operating conditions.
Hydraulic seals are designed to suit the cylinder working pressure, speed, operating temperature and fluid. Static hydraulic seals are located in a groove and see no movement; dynamic hydraulic seals are exposed to movement of the shaft or bore of a hydraulic cylinder. Common types include Piston Seals, rod Seals, wiper seals and wear rings.