When the flush valve on a Type IV system is placed in the pantograph flush mode, the solenoid is:

In a Type IV system, the flush valve's operation is crucial for proper functionality. When the flush valve is set to the pantograph flush mode, the role of the solenoid is to control the main valve's position. In this scenario, the solenoid becomes energized, which triggers the main valve to close.

This action is important to create the necessary pressure differential that allows for efficient flushing. By energizing the solenoid, it effectively directs the system to prevent fluid from flowing through the main valve, allowing for the proper flushing mechanism to engage and ensure that contaminants are cleared from the system effectively. Understanding this system response is vital for maintaining the water and fuel systems.