Fuel system

The image is of an Anderson 3 way fuel valve.  The valve has four detente positions.  

 

 

 

 

 

 

 

 

 

 

 

 

 

The configuration of the inputs is the T with a central output opposing the stem.  The valve has already been plumbed into the plane.  Right and Left input on the two arms of the T, and the base of the T is plugged.  The picture of the valve core below shows the input hole through the side of the valve core.

Fuel system valve core

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The way the system is currently plumbed both the up and down handle positions block the fuel flow.  This means that when changing between tanks you must pass through a closed position and this is not a preferred practice.  

While we could re-plumb the valve to have the base of the T and one side of the T be the inputs, thus not passing through a closed position when switching tanks, we prefer to use the valve as a BOTH/OFF valve.

Suggested modification of the valve is to make the port in the valve core pass all the way through the core.  This modification would give the condition of two BOTH (open) conditions, and two closed conditions.  Every 90° would change conditions.