Lugged Wafer Knife Gate

Sealing Principle

In the fully open position the valve is sealed to atmosphere through a combination adjustable stuffing box acting as the primary seal and a secondary transverse seal. The purpose of the secondary seal is to act as a scraper and extends the life of the primary seal.

As the valve closes the gate remains in contact with the mechanically retained moulded body seal throughout the stroke and is guided by the valve body. When the gate approaches the fully closed position, the angle between the blade and the flush-out corners create turbulent flow of the media over the seating area. The turbulent flow removes all the sediment from the seat which allows the gate to fully close on the seating area free from any slurry build-up.

When the valve opens the gate again remains in contact with the body seal and is wiped clean by scraper blades that ensure trouble free operation during the next closing cycle.