The EGR valve is usually an electrically operated pump fitted inside the water tank. The EGR valve applies a positive pressure helping the water travel to the engine along the water lines.
In most modern vehicles, the EGR valve is designed to provide a continuous flow of water to the engine and any excess water travels along a return line to the water tank.
Water-Injected Engines are monitored and controlled by an ECU (Electronic Control Unit) that can switch off the EGR valve if a collision is detected. This can also be achieved via an Inertia Switch
If the ECU detects a low oil pressure it may also switch off the EGR valve to prevent damage and the risk of fire
The water delivery system can be comprised of: