The common rail fuel relief valve works by utilizing a spring-loaded mechanism. The valve is designed to open when the fuel pressure in the common rail system surpasses a predetermined threshold. This threshold is usually set by the manufacturer to ensure optimal performance and safety.
When the pressure in the common rail system exceeds the set limit, the force exerted by the fuel pressure becomes greater than the opposing force exerted by the spring in the relief valve. This imbalance causes the valve to open, allowing excess fuel to flow out of the rail and back into the fuel tank.
By relieving the excess pressure, the relief valve helps to protect the fuel injection components, such as the injectors and the rail itself, from damage that can be caused by excessively high fuel pressure. It also helps to maintain consistent and stable fuel pressure within the system.
It is worth noting that the common rail fuel relief valve is just one part of the overall fuel system designed to ensure proper fuel delivery and pressure regulation in modern diesel engines equipped with common rail fuel injection systems.