Solenoid B on the 58AF-9-1 defuel/flush valve energizes to allow the main valve to open only when the?

The correct answer indicates that Solenoid B on the 58AF-9-1 defuel/flush valve energizes to allow the main valve to open specifically when the system is placed in the flush mode. This is essential because the flush mode is designed to clear any residual fuel from the lines and equipment, ensuring that the system is cleaned effectively. In flush mode, the operation of the solenoid and the main valve is crucial to bypass fuel flow and facilitate proper cleaning procedures.

When the system is in flush mode, it activates the necessary components, ensuring that the defuel/flush valve operates appropriately and allows for the efficient removal of fuel from the system. This process not only maintains hygiene and safety but also ensures the proper function and longevity of the equipment.

In contrast, other operational states such as manual or automatic starting of the fueling pumps do not directly relate to the activation of the flush function. The system needs to be explicitly in flush mode for the solenoid to engage and enable the necessary valve operations. Thus, the understanding of the specific context in which the solenoid operates is key to effectively managing the fuel and water systems.