The wear-resistant Ultrathan® Parker Prädifa AG wiper ring serves to prevent the ingress of dust, dirt, sand, and swarf at the rod eyes of a hydraulic cylinder. This reduces the risk of “seizure” on the swivel bolt due to external contamination. The good wiping effect is achieved by the special design of the wiper lip.

In addition, the wiper lip opens up during lubrication and allows excess grease to escape. The proven P5008 polyurethane compound stands for abrasion resistance, minor permanent deformation, and robustness against external mechanical impact. The wiper is securely held in place in the axially open groove via press-fit of the metal jacket vis-à-vis the inner groove diameter. As the wiper lip is flush with the rod eye it is largely protected against external mechanical damage.

• Robust seal profile for harshest operating conditions.
• Extreme wear
• Suitable for fully automatic
• Simple fabrication of the

Range of application

Hydraulic cylinders and valve tappets

Operating temperature                                    -35 °C to +100 °C

Sliding speed                                                    ≤ 2 m/s

Compounds

The standard material of the elastomer part is Ultrathan® P5008, a polyurethane-based Parker compound with a Shore A hardness of approx. 93. In comparison with other polyurethane materials currently available on the market, it excels because of its increased heat and wears resistance.

Installation

The Parker Praedifa profile AG Ultrathan® wiper rings are manufactured with a slightly oversized outer diameter D, thus ensuring a secure press-fit in the groove DH8 after installation. Any contact of the wiper lip with piston rod eyes or other connecting parts should be avoided.