Components whose job it is to seal areas under pressure in such a way that pressure levels are maintained. These are contact seals that may also be used at high pressures levels.
The materials used for hydraulic seals are predominantly elastomers and, to a lesser extent, thermoplastics. Metallic seals are now no longer relevant really. In terms of the arrangement, a distinction is made between piston seals and rod seals and, in terms of the form used, between grooved ring seals, lip seals, sealing sets and compact seals.