Paul or anyone.

My airplane specs. have a wet wing (leading edge D section) which are
divided into main and auxiliary long range tanks.  Total is about 110
gallons.  Holes are cut on both the middle bottom and front edge of the
D
shape ribs to allow fuel to flow down to the pickup for the mains and
another pick-up and pipe plumbed to the auxiliary.   That is four pipes
with
check valves, solenoids, side to side transfer pump for balancing the
plane
on the water. In addition the specs.  call for pieces of rubber to be
fastened over the  the ribs holes  to prevent backflow during turns.
The
rubber pieces are a joke. IMHO the design is less than admirable.

There must be a better design approach such as installing  simple
flapper
valves like those that are used in  hand fuel pumps or diving snorkels?

I would like to eliminate the four tank concept and just make the whole
leading edge into one tank thus having only two tanks to deal with.  Any
foreseeable problems with this approach?

Thanks

Doug in Japan

Can you send me a sketch jpg showing all the parts? Fuel systems
are extremely important.  Here is a picture of the metal flapper valves
used
in the Lancair IV and ES I suspect. I think they yield a certain
redundancy in a slip or uncorrodinated turn situation. The last thing
you want is an air bubble on the intake side of the high pressure pump.
The pump may fail to self prime when fuel is restored to the intake.
Particularly if the pump has cavitated in the past. If it does fail to
self prime it will rapidly over heat.

Paul Lamar

Paul,
It's not very clear from the picture, but these "Lancair flapper valves"
are fabricated from a couple pieces of sheet aluminum riveted to a short
piece of piano hinge.  They should be easy for anyone to make.  The
hinge pin should be longer than the hinge so it can be bent over to
prevent it from sliding out.  The "tab" at the top is to prevent the
flapper from getting jammed in the open position.  Once it is bolted
into place, Lancair instructs the builder to put a bead of micro around
the perimeter of the hole and then push the flapper up against it and
leave it to cure.  After cure, you pop it loose and you now have a nice
sealing surface.  Helps to put some packaging tape on the flapper before
pushing it into the micro.

Mark S.