The U-Cup is a single-acting sealing element. The U-Cup RU0 seal is installed with a simple snap fitting and seals statically on the outside diameter via a fixed seat. It has an asymmetric seal lip profile with shortened inner lip. This form can absorb deflections in the piston rod more easily than, e.g. U-Cup Form RU2 with its more rigid lip geometry. In pressure-free state, it exhibits lower frictional forces than double-lipped U-Cups
U-Cup RU1, is designed for small grooves. It is thus particularly suitable for use in space-saving designs. The compact form provides a high sealing effect even with low system pressures. The U-Cup has one sealing lip in the dynamic sealing zone. The compact form provides an improvement in the leakage behaviour at low system pressures.
U-Cup RU2, is designed for small grooves. It is thus particularly suitable for use in space-saving designs. The compact form provides a high sealing effect even with low system pressures. The U-Cup has two sealing lips in the dynamic sealing zone. The compact form with two sealing lips provides an improvement in the leakage behaviour at low system pressures. Due to the incorporation of an oil trap between the two sealing lips, friction at pressures above approximately 10 MPa is reduced. Furthermore, the second sealing lip prevents the entry of dirt from the atmosphere side.
U-Cup RU3, is used as a rod seal for heavy-duty conditions in mobile and industrial hydraulics. It is installed with a fixed seat at its outer diameter. The rear dynamic sealing lip improves the leakage behaviour and, at the same time, prevents the entry of contaminants from the atmosphere side. Compared with the RU2, the shorter inner lip is more flexible and can adapt better to the operating conditions and deflections of the piston rod
U-Cup RU6, Additional to the machined seals Stepseal® 2K and Rimseal for housings ISO 7425/2 (rubber energized plastic seals) the U-Cup RU6 has been developed as an injection moulded seal of polyurethane material to fit in the same ISO housings. The integrated NBR O-Ring (only available for series RU62 – RU64) improves the performance at low pressure and low temperature applications. Polyurethane (Zurcon® Z20) is a proven material for U-cups due to their good mechanical properties
U-Cup RU9, Rod seals are particularly exposed to pressure and friction and a long service life is a specific requirement of piston rods. Zurcon® U-Cup RU9 can offer this with its outstanding wear and extrusion resistance. It is also compatible with virtually all media, has a wide operating temperature range, and gives low friction. It has compact installation dimensions, is easy to assemble and can be used as a stand alone element with limitation to 40 MPa or in a tandem system with pressure up to 50 MPa.