The piston seals type Aston Seals KDA is mainly used with high pressure and the backup ring o!sets large gaps or structural deflections without extrusion. The asymmetric lips are designed to differentiate the behaviour of the lips on the static and dynamic surfaces: the static lip is
flexible, more sensitive to pressure fluctuations and it guaranties a wide contact area; the dynamic lip is shorter and stronger to concentrate load against the dynamic surface.
