N 6 X 12 X 6 AO1

PNNH U-Cup

PNNH U-Ring

U-Rings of series PNNH are used in the field of hydraulics for sealing pistons and rods up to an operating pressure of 160 bar. They have a particularly good sealing behavior and a high wear resistance. They can be used for sealing at even higher operating pressures up to a maximum of 360 bar in conjunction with support rings for reducing or closing the sealing gap(s) at the back of the seal.

The characteristic material projection extending beyond the sealing edge affords essential advantages as regards functioning of the U-ring. During expansion of the inner sealing lip by the rod, the resulting radial forces can only find support in the area of the sealing edge and this results in the fact that the tension force is at its maximum at the sealing edge. As a result of this, especially in the case of high viscous hydraulic oils or in the case of low starting temperatures, permeation of the sealing lip contact surface by the highly viscous medium is avoided and a good sealing effect is obtained. Even in normal applications, the required pressing of the seal is guaranteed by the sealing lip projection even if, over the course of time, the characteristics of the elastomeric material alter due to material fatigue and aging.

There is no need for front support rings with this design since the material projection extending beyond the sealing edge is adequately dimensioned to support the sealing lips at the groove wall.

Operating Conditions:

Maximum Speed: 0.5 m/s

Temperature: -30°C to 100°C (-22°F to 212°F)

Maximum Pressure: 160 bar