The inevitable fuel spill disaster

[WaiexB22]

Note: My Sonex centre tank, is filled vie either wing tank, so no fuel close to canopy.

What pump(s) are you using to transfer? How fast does it transfer?

[Skippydiesel]

A single Transfer pump, Facet Posi-Flow PN 60303. 7-10 psi,129 L/hr = 2.15L/min. It's slow but adequate. There is a wing tank selector valve - Left, Right, Off, that must be turned to the "active" tank.

I have 30 L in each wing tank and 35L in the fuselage tank. I mostly transfer in the air but on occasion, top up the fuselage tank on the ground and then fill both wing tanks.

My son has made me a semi automatic fuel transfer system (can be turned to manual) that works very well. I just select the wing tank I want to use, press the Auto Fill button and the Transfer pump starts. The Auto Fill works on fuel level and on time. If its taking to long for the fuel to get to the preset 35L level, it will time out and stop the pump.

My fuel return line, about 7L/hr, goes to the fuselage tank.

I can use my Boost pump ( Facet Cube PN 40135, 4-7psi, Flow 121.13L/hr = 2L/Min) on any of the three tanks for TO/Landings, however it's simpler to just use the fuselage tank.

[13brv3]

13brv3,

On the matter of pump priming - from the photo it looks very like your pump is a centrifugal type. Centrifugal do not easily self prim when mounted above the liquid source.

The Fill-Rite folks are very quick with replies to questions. Priming is indeed the issue. They said the automatic nozzle requires 4psi to actuate, and the centrifugal pump can't generate that much pressure if it's lost prime. I do have a few options to get it working, and I'll definitely be reinstalling the automatic nozzle.

[13brv3]

I think I've pretty much settled on the new fuel funnel. It seals to the inside of the tank neck with an o-ring, and should dump any overfill or spill harmlessly on the cowl. Now I just have to be vigilant about using it.