For housings according to ISO 5597/I.

The Parker Prädifa rod sealing set profile M5 is adjusted to the housings of ISO 5597/1 (light series) and may be used for the same working conditions as the profile M2. In order to reach the necessary set height “H” these packings are available with 2 or 3 fabric-reinforced and one rubber chevron. The header rings may be produced either of hard-fabric or of plastic; the back-up rings are always made of hard fabric.

Field of application:

Working pressure:                  ≤ 350 bar

Working temperature:         – 40 to + 100 °C

Surface speed:                         ≤ 0,5 m/s

Chevron sealing sets are well suited for the sealing of plungers, piston rods of presses, cylinders, valve shafts, and spools, even in difficult working conditions. Thus they can be recommended for use where the actual conditions are difficult to predict.

Compounds:

Back-up ring: Hard fabric, NBR-based (0502 Q5022).

Chevrons: Fabric reinforced rubber material, NBF-based (Q5018/05019)  resp.  NBR  elastomer (N3578).

Header ring: Polyacetal (POM-W5001) or hard fabric, NBR-based (Q5021/05022).

Installation:

Due to the relatively low elasticity of the fabric chevrons and the required axial preload of these sealing sets, an installation groove, which is open on one side has to the provided. The actual height of the set is normally in accordance with the length “L” of the housing. Manufacturing tolerances of the seals and the metal parts (especially in case of large dimensions) may be compensated for by screwrings or shims in order to achieve an optimum function. (Adjustability at least 5 % of the length “L”).

When strongly squeezed the flexibility of the sealing set may be substantially reduced. Thus it could be transformed to act as rod guidance with excessive friction and high wear. Due to the adjustability, it is possible to use these sets for special applications: For example in case of high speed, exceptionally large temperature range, strongly varying pressure, or a combination of these parameters. The various components of the set must be installed individually according to their sequence within the set. Oiling or slightly greasing will facilitate the assembly. Fabric chevrons with relatively large cross-sections can be made more flexible by slightly kneading them in warm oil.  This will facilitate the installation considerably. For easier maintenance, the sealing sets may also be slit. The chevrons and the back-up ring are cut at 45° angle, the header ring with a 90° angle. The cuts of the components must be staggered by 120° at installation, which will not alter the length of the housing.