Why check valve is employed in parallel with flow control valve?

A check valve is employed in parallel with a flow control valve to prevent backflow in a system while allowing for precise control of flow rates. This configuration ensures that if the flow control valve closes or is adjusted, the check valve will automatically prevent any reverse flow that could disrupt system operation or damage components. Additionally, the check valve helps maintain the desired pressure and flow direction, enhancing the overall efficiency and safety of the fluid system.