What position must the fuel tank valve be in for the P-100 pump to operate properly?

For the P-100 pump to operate properly, the fuel tank valve must be in the "Open" position. This is essential because the pump requires a continuous flow of fuel to function correctly. If the valve is closed, the pump would be starved of fuel, leading to cavitation, overheating, and potential damage to the pump. A half-open position may not provide sufficient fuel flow, which could also hinder the pump's efficiency and performance. Having the valve completely sealed would entirely prevent any flow, making it impossible for the pump to draw in fuel at all. Therefore, ensuring that the valve is open allows for adequate fuel supply, enabling the pump to operate as intended.