The 106-DW and 206-DW deep well pump control valves are installed in a tee between the pump discharge and the check valve.
The valve is normally open, and, on pump start-up, a pilot solenoid is energized to start closing the valve at a rate governed by the closing speed control.
Initially, the valve discharges air, water and sand to waste. The open valve discharges all pump flow. As the valve closes slowly, flow is transferred to the main line smoothly, increasing the pipeline flow without surges. When the valve is fully closed, all pump flow is in the pipeline, with no control valve losses.
When shut-down is required, the pilot solenoid on the valve is de-energized to commence opening. The pump is kept running while the valve slowly opens. Increasing proportion of the flow is diverted to waste with less passing through the check valve, until all flow is diverted through the nearly fully open DW valve. The pipeline check valve closes quietly without surges. When the DW valve is almost fully open, a stem mounted cam triggers the limit switch to stop the pump.
For more information on the 106 / 206-DW Deep Well Pump Contol Valve: