Polyurethane U-cup rod seals

U-cup seals, as their name implies, have a U-shaped profile, including an outside static sealing lip and an inside dynamic sealing lip. The unique combination of resilience and its resistance to gap extrusion and wear makes thermoplastic polyurethane (TPU) the most common material used for U-cup seals in hydraulic applications.
They are available with a single- or double-lip design.

S1S profiles

S1S profiles (fig. 1) are made of ECOPUR (TPU) and have a single-lip design. The geometry has been optimized using FEA (Finite Element Analysis) to provide the longest possible maintenance-free service. They are suitable for pressures up to 400 bar (5 800 psi) in medium to heavy duty applications and are available in metric sizes (→ Size list [pdf]). Some fit seal housings in accordance with ISO 5597:2010. For additional information, refer to S1S profile data.

ZBR profiles

ZBR profiles (fig. 2) are made of LUBRITHANE (TPU) and have a double-lip design. They are suitable for pressures up to 400 bar (5 800 psi) in medium to heavy duty applications and are available in metric (→ Size list [pdf]) and inch sizes (→ Size list [pdf]). Some metric sizes fit seal housings in accordance with ISO 5597:2010. For additional information, refer to ZBR profile data.

SIL profiles

SIL profiles (fig. 3) are made of etherbased TPU. They have a douple-lip design and a secondary dynamic sealing lip. These seals provide good resistance to hydrolysis (attack from moisture) and good low temperature resilience. SIL profiles are suitable for pressures up to 350 bar (5 075 psi) in light to medium duty applications and are available in metric sizes (→ Size list [pdf]). Some fit seal housings in accordance with ISO 5597:2010. For additional information, refer to SIL profile data.
SKF logo