A single-acting rod seal, Zurcon® L-Cup® is an alternative to the U-Cup. It is a highly effective sealing system offering optimized sealing performance and extended service life. With exceptionally low friction properties, it has high wear resistance, back pumping ability along with high static and dynamic tightness.


The rod sealing system is the most critical part of a hydraulic cylinder. Therefore it is expected

that a rod sealing system performs under leakfree conditions in the static and dynamic state.

Moreover it has to fulfil a lifetime of several thousand hours. To meet these requirements, Trelleborg Sealing Solutions has developed the Zurcon®l-Cup®*, a highly effective and


innovative rod sealing component.






Pressure: up to 40 MPa

Velocity: up to 0.5 m/s

Temperature: -35 °C to +110 °C (Zurcon®Z20 standard)

Media: Hydraulic fluids based on mineral oil



- Hydrodynamic back-pumping ability over the complete working pressure range

 - low friction and therefore a reduction of heat generated

 - low breakout force even after a long period of non-operation

 - Very low stick-slip

 - low increase in friction at increasing pressure

 - High extrusion resistance

 - optimum geometry of the static sealing lip for higher sealing ability

 - no entrapped oil and grease between seal and groove (due to notches)

 - no pressure build-up between seal and groove oD

 - long service life The Zurcon®l-Cup®was designed in accordance with customers' demands.

 - groove dimensions according to iSo 5597 Part 2

 - interchangeable with existing u-Cup grooves

- installation into closed grooves

 - Wear and extrusion resistant high-performance polyurethane