An altitude valve is a pilot-operated valve that opens and closes to fill a high-level tower or tank hydraulically. The valve performs this function by sensing the static level of water in the tower.
The control valve has a high-sensitivity three-way positioning pilot that diverts water to the control chamber once the top level is reached, thereby making the valve close.
When water is at a low level in the tower, the pilot senses the need to open. In these instances, water is vented from the chamber, making the valve open to re-fill the tank.
The difference between opening and closing of the tank is pre-set in the pilot to approximately one metre. However, if greater differentials are required, a send pilot is fitted to create an adjustable differential between opening and closing.
