This example shows a pressure-compensated 3-way flow control valve. This valve maintains constant flow rate through the main hydraulic motor, which is connected to the pressure-compensated outlet of the flow control valve. It acts as a priority valve, diverting the excess flow to the auxiliary hydraulic motor if the main hydraulic motor receives enough fluid to maintain a preset angular velocity. The auxiliary motor is shut off completely if there is insufficient flow to power the main hydraulic motor.
The plot below shows the flow rates through the priority valve. As the flow rate at the inlet varies, the main motor is driven at the desired speed and excess flow is directed to the auxiliary hydraulic motor. When the inlet flow drops below the threshold to maintain the speed for the main hydraulic motor, the main motor slows down as well.