What position must the GCU-30 fill station valve be placed in before removing the tank?

The fill station valve of the GCU-30 must be placed in the bleed position before removing the tank to ensure safety and prevent fuel from flowing during the removal process. When the bleed position is selected, it allows any residual fuel pressure in the system to be released, thus minimizing the risk of spills or accidents that could occur if the valve were in an open or closed position. This procedure is crucial to maintain operational safety and compliance with handling protocols. Using the bleed position helps to prepare the system for maintenance or tank replacement while ensuring that personnel are protected from potential hazards associated with fuel handling.