Mailing List flyrotary@lancaironline.net Message #28606
From: Ernest Christley <echristley@nc.rr.com>
Subject: Re: [FlyRotary] Re: Fuel filter selection
Date: Tue, 20 Dec 2005 10:43:53 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Buly wrote:

Guys, I don't understand why you are installing filters AFTER the  pumps? I sell large SEPAR diesel fuel filters and I always recommend  all the filtering to be done before the pumps and out of the tanks.
 Any water or debris if it's allowed to reach the pumps, will be  beaten into smaller particles and may be PUSHED thru the filter, or  even will damage the pumps.
I personally suffered on my boat by frequent engine stopages in the  worst of times, only to discover that the manufacturer have installed  a screen on the pick up tube inside of the tank, where can not be  seen or cleaned.
The same manufacturer had to fix or replace number of engines only  because he installed the fuel pumps BEFORE the filter. Any water in  the fuel was beaten in to fine emulsion and pushed thru the filter  into the injectors. Results were rusted injectors, rusted high  pressure pumps and more.
Buly

Seems to be a lot of debate on this one, Buly.  Filter before the pumps and you'll die from vapor lock.  Filter after the pump and you'll die from rusted injectors.

My solution, as recommended by others, is a PRM-81794 filter/water seperator before the pump.   This is a high flow unit with dual 1/2" inlets and outlets that filters down to a few microns.  Then a Summit Racing 40-micron inline filter after the pump. The first should insure that everything is clean and dry.  The second will catch most debris that a failing pump or pressure regulator might throw.

The PRM-81794 has a valve on the bottom of the filter.  I presume that is to drain any collected water.  Has anyone investigated semi-permanently attaching a hose leading to an easily accessible drain?

--
        ,|"|"|,                                    |
----===<{{(oQo)}}>===----        Dyke Delta         |
       o|  d  |o          www.ernest.isa-geek.org  |
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster