Paul,
There is a substitute for a flapper valve that has no moving parts and does
almost the same thing.  Since I haven't figured out how to draw a picture on
this $#@#%$# machine, I will try to describe it.

Let rib "A" be the inboard end of the tank, and rib "B" the next outboard
rib. Rib B has the normal top vents but the gas has to flow through two tubes
that have there outboard end flush with rib B in the same area as you would
have fuel flow openings in that rib, and go to within an inch of rib A.  All
other areas in the rib are sealed.  Schedule 20 PVC works well for this.
     You can still unport the pickup tube in a hard slip, (as you can with a
flapper valve) but you trap all the fuel that remains between rib A and
B  when the inboard end of the tubes become exposed.

     And no moving parts!

Bob Darrah

I think I can picture that. Looks good. Is that part of some kit?
Why not run the pickup tube to within an inch of rib B? Or perhaps
half way over.

Paul Lamar
 
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