Can this be used not only as a water flow sensor but also a valve to control the rate of flow through it?
Perhaps if the sensor was a rotor connected to a motor/generator when in one instance you could read the voltage from the generator to determine flow and in another instance send a voltage to it to make it act like a motor and restrict flow. Note that I said restrict flow not completely turn it off. But the amount of restriction would probably be questionable and most likely negligible. But, these sensors are designed to provide the least amount of restriction to flow. Hence the use of a hall-effect sensor. Here the wheel/rotor’s movement is only affected by the flow of the fluid. it cannot be influenced by any other means external to the device.