The construction machinery and general mobile equipment industries require efficient rotary transmissions for hydraulic fluids. This applies in all cases where the use of hoses is not practicable for reasons of safety, function, or lack of space.

Parker took into consideration the compact design of these rotary transmissions and designed equally compact sealing elements which can be snapped into simple grooves.

There are two different types of Parker Prädifa rotary seals: For the stator with dynamic sealing on the inside, and for the rotor with dynamic sealing on the outside diameter of the seal.

Care must be taken to ensure that the high-pressure channels are placed towards the center, whilst the return, the low pressure, the control, and the leakage channels are placed towards the end (atmospheric side) of the rotor. This will ensure that the highly stressed high-pressure seals are lubricated and cooled from both sides and that no contamination may penetrate from outside. Due to the reciprocal pressure load, the back-up rings will also be sufficiently lubricated. As the end seals are subjected to low pressure only the problem of contamination and abrasion is here of less importance.

The rotor Parker Praedifa seal profile C9 consists of a wear-resistant rubber seal equipped with a back-up ring to increase the stability and to prevent extrusion into the gap, especially for applications where eccentricity occurs. This seal, specially designed for end-sealing, can also withstand temporary pressure peaks.

Field of application:

Working pressure:                ≤5 40 bar

Working temperature:         — 30 to + 100 °C

Surface speed:                        ≤0,2 m/s

Mainly for use  as  an  end-seal  in  all  rotary
transmissions of construction machinery, mobile
hydraulics and machine tool hydraulics, as well as for low-pressure swivel joints.

Installation:

These seals are designed to be snapped into closed grooves. First, the sealing part must be installed.
followed by the back-up ring. To avoid damaging the seal, sharp; edges within the installation area
should be removed.

Compounds:

The standard compound for the rubber sealing is a
NBR-based elastomer (N3584) with a hardness of approx. 84 Shore A. The back-up ring is made of a polyacetal-based material (W5001).

For special requirements (pressure, temperature, speed, etc.) please contact our Consultancy Service so that suitable materials and/or designs can be recommended.

d	D	H	L	Item number
30	42	7	8	C9 0030 00656
30	8	9	10	C9 0090 00656
90	10	10	11	C9 0091 00656
105	25	10	11	C9 0105 00656
115	35	10	11	C9 0115 00656
130	50	10	11	C9 0131 00656
140	60	10	11	C9 0140 00656
160	80	10	11	C9 0160 00656
170	90	10	11	C9 0170 00656
200	20	10	11	C9 0200 00656