The valve opens fully or shuts off in response to electric signals. The valve is controlled by a solenoid that allows control liquid to flow in the upper chamber in order to close the main valve or, alternatively, drains upper chamber in order to open the main valve.
This valve protects pumps and pipes from pump startup and shutoff pressure surges due to power failure. Pump off means valve normally closed. If pump starting cause pressure surge, the pilot smoothly opens the valve to limit pressure rising.
This valve controls water level in high level reservoirs to avoid overflow, without any external control system like float control etc. The valve remains completely open until the closing input is transmitted by the 3-ways piezometric altitude pilot.
The valve reduces high upstream pressure to a pre-set lower and constant downstream pressure level, regardless of fluctuating flow or varying upstream pressure. A hydraulic regulating pilot drives the valve. The pilot is able to detect upstream pressure values and regulates closing steps of the valve until the pre-set pressure value is restored.
The valve controls downstream flow to a pre-set and constant value in order to limit water consumptions and preserve pipeline fill rate or to set a maximum demand value. The valve is controlled by a differential hydraulic pilot that senses the pressure fall generated by water flow into a calibrated orifice.