Still another method, that evolved in my 235 due to two Facet pump failures
in the first two-three years of operation. I have a header tank and the
engine is normally aspirated.

Each wing tank is plumbed directly to a R - L selector valve, then to two
Facet pumps in series under the pilot's seat, then on to the header tank.
From header via shut-off valve to the gascolator, followed by a Facet boost
pump and then on to the engine driven pump.

I retain the two transfer pumps, but if either one fails I can still access
fuel in both wings.

Just another method for your consideration.

Dan Schaefer