Trojan F44. Fuel cross over valve

[Pcravens]

What does this valve do and what is it for. This boat has 4 tanks 2 main and 2 auxiliary. It has 2 fuel valves that can be off , main or auxiliary. And one on n off for the generator. And it has another one in the middle that has cross over on or off on it. Not sure what that valve does. Thanks

[prowlersfish]

It is used so can pull fuel from the other side. Example: Open the cross over and close the port side valve and both engines would draw from the starboard side or vice-versa. In normal opp you would leave it closed (off)

If this is a diesel there is more to it. But again leave it closed.