Altitude Control Vertical – 6ALT
The Altitude Control function controls the water level in a reservoir from 6m up to an altitude of 45m above the Main Control Valve. The Main Control Valve is controlled by an altitude pilot that senses the change in head of the water through a sensing line. The pilot valve controls an accelerator valve, which in return controls the Main Control Valve. When the supply line is not pressurised, the Main Control Valve will act as a non-return valve, preventing the drainage of the reservoir back into the supply line. On reaching a high level in the reservoir, the pilot pressurises the Main Control Valve Chamber and closes the valve. When the reservoir water level drops, the pilot drains the water from the Main Control Valve Chamber and opens the valve.