The Parker Prädifa cylinder sealing set profile NO is manufactured in two parts and consists of a fabric reinforced symmetrical lip ring and a back-up ring made of fabric reinforced hard rubber. The lip ring has integral support thus obviating the necessity for separate header rings as found in normal seal ring arrangements. The header ring prevents extrusion damage to the lip ring occurring in the clearance between the piston and the cylinder wall.

The sealing set offers the following advantages in heavy hydraulic equipment:

• High resistance to extrusion through a massive fabric reinforced header ring.
• Due to the favourable profile design, there is no dynamic pressure build-up between the sealing elements in double-acting cylinders.
• Through the choice of suitable materials, the seal is adapted for various working media.
• Excellent sealing function at high surface speeds or under high pressures.
• Long working life keeps maintenance costs down.

Field of application:

Working pressure:                  ≤ 500 bar

Working temperature:         — 40 to + 100 °C

Surface speed:                         ≤ 1 m/s

Preferably used for double-acting pistons in hydraulic cylinders.

Installation:

Groove dimensions agree with those for the Parker Praedifa profile NG series. It is to note that the sealing set must not be drawn over sharp edges or threads during assembly. This avoids damaging the lips. The value for, »e« are maximum values for completely worn out wear rings (see chapter A “Gap sizes”).

Compounds:

Sealing ring:  NBR-based hard fabric reinforced rubber (05015/Q5016).

Back-up ring: NBR-based hard fabric reinforced rubber (05021/05022).

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