NOPE!
In pressure mode, the filter will also act as a 'coalescer' (bringing
similar surface tension fluids together to make larger and larger sized
particles) and such particles will settle out into a 'drop-out-pot'
...... or usually into the bottom of the filter bowl (bowl pointing
downwards). The smaller the retention size of the filter media the
more efficient the coalescing efficiency.
On the very bottom of the filter bowl, add a pigtail of oil compatible
transluscent plastic tube (Tygon, etc.) with a cock on the end ....
when you see water in the pigtail simply drain the bowl. Thats the
same way a racor with an integral clear plastic knock-out-pot works.

If you are regularly polishing the fuel the coalesced emulsions will be
removed/trapped in the inverted filter bowl .... that why you put the
dip tube for the recirc system at the VERY bottom of the tank and a
drain cock on the inverted filter bowl.

Dont want air leaks or fuel oil leaks ------ dont use compression
fittings, use flared or better fittings.

Pump should have a SCREEN (preferably integral) for protection to
prevent damage by *huge* particles that would tear the rubber impeller
or wobble plate.

I say again, if you want long service life and efficient filtration
employ PRESSURE filtration, especially on a recirculation system.

The ONLY reason I can think of why fuel systems in boats use vacuum
filtration is ........... the engine manufactures supply the lift pump
and 'guard' filter - and puts it on the engine ...... and not on the
tank (where it SHOULD BE). Cheap and dirty solution, easier for the
boat builder - less wiring, less design, less effort, ....



In article k.net,
Rick wrote:

Doug Dotson wrote:
I am assembling my posihing system. Not clear whether it is better
to put the pump on the pressure side or the vacuum side. Having no
filter on the intake of the pump seems risky. I am using a 2 stage
approach. maybe putting the filter between the filters is an option.

You want to avoid having the pump act as an homogenizer. If
the pump takes suction directly from the tank it will
thoroughly mix all the water and crud that you want to
filter out. This makes it much more difficult to remove in
the filters.

The Racors operate best on the suction side because the
separator section of the filter will, when it receives one,
deposit a clean slug of water in the bowl rather than clog
the filter media with an emulsion created by the pump.

Rick