Rick wrote:

Steven Shelikoff wrote:

IOW, even if the pump is past the filter drawing fuel through it, the
filter is still in "pressure" mode because it's really the atmospheric
pressure pushing fuel through the filter.


The difference is that if the pump suction pulls water and fuel directly
from the tank it will do an excellent job of mixing it up to form an
emulsion that will not filter out very effectively.

Then it sounds like it would be better to have the pump past the filters.

The path should be, a basket strainer to catch the chunks, a
separarator/filter to eliminate the bulk of the water and the smaller
suspended particles, the pump, then the finer stages of filtration.

Well, now I have to ask why the pump should be before the finer stages
of filtration. It seems to me that as long as it can maintain a
sufficient pressure differential across all the stages of filtration, it
wouldn't matter where the pump is. Of course if it can't do that (not
enough suction for all the stages before it) then you'd have to move the
pump up in the stream like you suggest above.

This is all assuming you don't have access to a centrifuge which is
really the best way to handle the process.

I do, but it's a little big to fit on the boat.

Steve