The popularity of high-pressure water cleaning equipment has led to even more exacting demands being made on seals fitted to the water pump. For example, seals often have to operate in hot water, with high pressures on the pumping stroke and vacuum on the suction stroke. In the early cleaning equipment, the seals originated from oil hydraulic
components.

Oil seals were often used for sealing the gearbox. With these seals, it was impossible to meet the exacting demands of the suction stroke and the hot water. These seals also had a short service life. Damage to the pump motor was a common failure. It was caused by water passing the seal and entering the lubricating oil. Another common failure was damage to the surface of the plunger because the seals were too tight. Overcoming these problems led us to develop a new sealing system where the seals are carefully designed for the water and gearbox oil to ensure long service life. Our Parker Prädifa system uses three profiles W1, W2, and W7. It has features that overcome the earlier problems.

A special profile front ring for the suction operation. An additional lip on the gearbox seal preventing damage by water penetration. No pump failure through sticking or damaged plungers. The seal system design incorporates features based on value analysis which results in a sealing concept that can withstand extreme pressure variations, high temperatures, and minimal lubrication. High-pressure cleaning equipment incorporating these seals will meet the most exacting demands of the user.

Field of application:

For high-frequency oscillating plungers.

Working temperature:        up to + 100 °C

Surface speed:                        ≤ 2 m/s

Suitable for motor oils up to SAE 50. Gearbox oils up to SAE 90 and hydraulic oils up to ISO VG 100.

Installation:

This reinforced seal has the metal completely enclosed and the contours provide a gearbox seal with good static sealing and secure seating. If the open groove is provided with a chamfer it is recommended that the external surface be lightly lubricated before being pressed into the recess. Installation should only be done with an insertion tool and press. Care is needed to prevent the Parker Praedifa seal from being pushed too far into the groove and deforming of the seal lip. For optimum service life carefully lubricate the seal running surface and the plunger with oil from the gearbox.

Compounds:

Standard compound for the rubber component is an NBR elastomer 78 Shore A hardness.

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