Over/underpressure safety device for the sewage plant industry (e.g. digesters)

The over/underpressure safety device developed by Kopf is designed specifically for every application. The individual operating states are shown in the adjacent diagram.
Before commissioning, the cup is filled with water via the neck. In normal operation, the second figure in the graphic, the water head is deflected. The advantage of this system is that water can be refilled at any pressure without changing the maximum overpressure. In figure 3, the water cup is in a filled state with operating pressure.