A diagram of an AGA BM Oil Control Valve is a visual representation of the valve’s internal components and how they interact with each other. It shows the location of the various parts of the valve, such as the inlet and outlet ports, the actuator, the stem, the disc, and the spring. It also illustrates the flow of oil through the valve and how it is regulated. The diagram is useful for troubleshooting and understanding the valve’s operation. It can also be used to identify potential problems with the valve and to help diagnose any issues that may arise. By understanding the components of the valve and how they interact, technicians can quickly and accurately diagnose any problems that may arise.