The Parker Prädifa piston sealing set profile M4 seals the piston against the cylinder. This sealing set consists of a chevron with a header and a back-up ring. By the proper choice of compound for the chevron seal, this sealing set may be adjusted for a large variety of working conditions. For example, The chevron seal could be supplied
with NBR material without fabric reinforcement, thus allowing use at low temperatures or in case of exceptionally severe sealing situations.

Installation:

For the installation of these Parker Praedifa seals, a two-piece piston is essential. Care should be taken that the sealing set is not drawn over sharp edges or threads during installation. The piston should be designed so that the sealing set can be installed with the header ring rear surface first so that a slight inlet slope or a radius at the centerpiece of the piston will be sufficient to facilitate the installation. The values for »e«  are maximum values with completely worn out wear rings (see chapter A “Gap sizes”).

Field of application:

Working pressure:                 ≤ 500 bar

Working temperature:         -40 to + 100 °C

Surface speed:                        ≤ 0,5 m/s

Preferably to be used for double-acting pistons for sealing cylinders.

Compounds:

Back-up ring: NBR-based hard fabric compound  (05021/Q5022).

Chevron ring: NBR-based compound with fabric reinforcement (05018/05019).

Header ring:   Polyacetal (POM-W5001) or NBR-based hard fabric (05021/05022).

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