Subject: Fuel transfer/polishing pump
From: Jere Lull
You don't want too fine a filter on the suction side. On Yanmars (and
others), the lift pump can fail sooner due to the restriction.
My point is if you use a large surface area small micron filter and change it
regularly, you should never see high suction pressures.
The idea
is to do the cleaning in stages: 30 micron before the lift pump, 10
micron just before the high pressure pump. That said, we used 10 micron
Racor elements for 8-9 seasons and 1000 hours with no significant ill
effects except when we got a shot of algae.
8-9 years without changing the element! Your perpetuating a stereo type Jere.
:-)
The on-engine filter never
had any significant dirt on it (or in the bowl). That didn't change much
when we went to 30 microns, as it happens.
Note: We were able to limp home when the last filter on board clogged up
during the algae incident: Pulled the filter and gently brushed junk off
of the surface, and drained and cleaned the bowl (again). For a couple
of hours, we could only pull half revs, but the fuel cleaned up nicely
at reduced flow and (after draining the dead bodies from the bowl again)
we had full power for the rest of the season.
Yeah, been there, done that. Lots of fun when there's a sea running.
Capt. Bill