Which valves should be opened for defueling operations in the SIXCON system?

In the context of the SIXCON system, defueling operations require specific valves to be opened to ensure the fuel is properly transferred from the tank to the desired location. The correct choice indicates that valves B and D should be opened for this process.

Valve B is typically responsible for controlling the flow from the fuel source or tank, facilitating the movement of fuel during defueling operations. By having this valve open, fuel can exit the storage area efficiently.

Valve D is likely involved in the outflow path to an external system or container, ensuring that the fuel being released from the tank is directed accurately and safely away from the system.

Opening both these valves allows for a coordinated flow of fuel during defueling, minimizing the risk of pressure buildup and ensuring that the operation adheres to safety protocols. Properly understanding the function of these valves is crucial for ensuring effective and safe defueling operations.