X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 2 [X] Return-Path: Received: from ms-smtp-04.southeast.rr.com ([24.25.9.103] verified) by logan.com (CommuniGate Pro SMTP 5.1.7) with ESMTP id 1907092 for flyrotary@lancaironline.net; Wed, 07 Mar 2007 10:03:12 -0500 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.103; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-103-061.carolina.res.rr.com [24.74.103.61]) by ms-smtp-04.southeast.rr.com (8.13.6/8.13.6) with SMTP id l27F27qX017117 for ; Wed, 7 Mar 2007 10:02:07 -0500 (EST) Message-ID: <001801c760c9$94190870$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] fuel filter Date: Wed, 7 Mar 2007 10:02:08 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0015_01C7609F.AAFDE120" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3028 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0015_01C7609F.AAFDE120 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi John, There has been some debate about where the filter should go. Some folks = feel its purpose is to protect the pump and place it before the pump, = others feel it is to prevent clogging of the fuel injector screens and = place it after. I personally believe placing a high pressure filter after the pump is = the preferred solution. I use a coarse filter (wire mesh) before the pump to keep any large foreign matter out of the = pumps. If your injectors clog it doesn't matter what kind of filter you = have before the pump or how well the pump is protected. Others will = argue that a fine filter before the pump protects both - unless of = course the pump starts to shed material. One thing to consider is that a filter of any kind will cause a pressure = drop, the finer it is (and therefore the more restrictive) the more of a = pressure drop. Pressure drops before the intake of a pump can lead to = cavitation and formation of bubbles in the fuel line leading to "vapor = lock".=20 In the auto, the screen inlet in the tank acts like a coarse filter ( = before the pump) and the filter outside the tank is a finer filter. There you have my 0.02 on the topic Ed ----- Original Message -----=20 From: John Downing=20 To: Rotary motors in aircraft=20 Sent: Wednesday, March 07, 2007 9:50 AM Subject: [FlyRotary] fuel filter Looking at the pictures of fuel filter, pump installations, the filter = is after the pump. In auto installations the pump in tank has a = screened inlet and then filter someplace between the pump and the = injection system. The plane has a gascolator and do I place the pump = next like auto installations, then into the filter like the auto = installations, or why not. JohnD ------=_NextPart_000_0015_01C7609F.AAFDE120 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi John,
 
There has been some debate about where the = filter should=20 go.  Some folks feel its purpose is to protect the pump and place = it before=20 the pump, others feel it is to prevent clogging of the fuel injector = screens and=20 place it after.
 
I personally believe placing a high = pressure filter=20 after the pump is the preferred solution.  I use a coarse = filter
(wire mesh) before the pump to keep any large = foreign=20 matter out of the pumps.  If your injectors clog it doesn't matter = what=20 kind of filter you have before the pump or how well the pump is = protected. =20 Others will argue that a fine filter before the pump protects both - = unless of=20 course the pump starts to shed material.
 
One thing to consider is that a filter of any = kind will=20 cause a pressure drop, the finer it is (and therefore the more = restrictive) the=20 more of a pressure drop.  Pressure drops before the intake of a = pump can=20 lead to cavitation and formation of bubbles in the fuel line leading to = "vapor=20 lock".
 
In the auto, the screen inlet in the = tank acts like a=20 coarse filter ( before the pump) and the filter outside the tank is a = finer=20 filter.
 
There you have my 0.02 on the topic
 
Ed
----- Original Message -----
From:=20 John=20 Downing
Sent: Wednesday, March 07, 2007 = 9:50=20 AM
Subject: [FlyRotary] fuel = filter

Looking at the pictures of fuel = filter, pump=20 installations, the filter is after the pump.  In auto = installations the=20 pump in tank has a screened inlet and then filter someplace between = the pump=20 and the injection system.  The plane has a gascolator and do I = place the=20 pump next like auto installations, then into the filter like the auto=20 installations, or why not.  = JohnD
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