The process is actually quite simple. When you need to change the flow inside a particular piping system, whether to stop or start it, reroute it, change the pressure or modify its velocity, all you need to do is to send a low-powered electrical signal to the appropriate servo valve in your system using a digital control panel.
This low-powered signal goes through an amplifier, which boosts the signal until it becomes strong enough to change the position of the servo valve.
The strong textservo valve then manipulates the actuator (the equivalent to a simple kind of hand wheel) into carrying out the changes you want to see happen with the flow.
And because the system is closed-loop, feedback is directed to the servo valve. This feedback enables the servo valve to generate a more accurate response to the received command.