X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 21 Jun 2009 20:30:03 -0400 Message-ID: X-Original-Return-Path: Received: from betsy.gendns5.com ([65.254.38.234] verified) by logan.com (CommuniGate Pro SMTP 5.2.14) with ESMTPS id 3689309 for lml@lancaironline.net; Sat, 20 Jun 2009 09:22:02 -0400 Received-SPF: none receiver=logan.com; client-ip=65.254.38.234; envelope-from=paul@tbm700.com Received: from adsl-35-179-137.dab.bellsouth.net ([67.35.179.137]:1686 helo=[192.168.1.122]) by betsy.gendns5.com with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.69) (envelope-from ) id 1MI0VY-0006ym-IN for lml@lancaironline.net; Sat, 20 Jun 2009 09:21:24 -0400 X-Original-Message-ID: <4A3CE246.2070806@tbm700.com> X-Original-Date: Sat, 20 Jun 2009 09:21:10 -0400 From: paul miller User-Agent: Thunderbird 2.0.0.21 (Windows/20090302) MIME-Version: 1.0 X-Original-To: Lancair Mailing List Subject: Re: [LML] Boost Pump Question and FL220 flameout References: In-Reply-To: Content-Type: multipart/alternative; boundary="------------080005090808080402090601" X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - betsy.gendns5.com X-AntiAbuse: Original Domain - lancaironline.net X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - tbm700.com This is a multi-part message in MIME format. --------------080005090808080402090601 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Bill: One more item to consider is bent/kinked fuel lines. Sharp bends or kinks or restrictions in the lines can prompt vapor formation. Paul Miller William Miller wrote: > > 1. Fuel tank _V_ent blocked creating _v_acuum in the tank > (Why is there no "crossfeed _v_ent" between upper tanks? or valve > between _v_apor return lines? Or is there?) > 2. Negative/zero G's exposing the tank gravity feed outlet to air > (okay mostly N2, but still N2_ V_apor). > > 3. _V_apor in the lines before the selector _V_alve > 4. _V_apor leaking past the fuel selector _V_alve O-rings from the > pressurized cabin > 5. _V_apor in the line feeding the EDFP around the accessory case > especially in a hot climb > 6. _V_apor anywhere else the fuel line runs next to a heat source, > though less likely in the higher pressure areas. ( Anybody have a > triple point chart for 100LL? Marv has a nice graph on 2/2/07 -- but > no pressure axis or contour/family of curves... yet ) > > --------------080005090808080402090601 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 8bit Bill: One more item to consider is bent/kinked fuel lines. Sharp bends or kinks or restrictions in the lines can prompt vapor formation.

Paul Miller

William Miller wrote:

1. Fuel tank Vent blocked creating vacuum in the tank
(Why is there no "crossfeed vent" between upper tanks? or valve between vapor return lines? Or is there?)
2. Negative/zero G's exposing the tank gravity feed outlet to air (okay mostly N2, but still N2 Vapor).

3. Vapor in the lines before the selector Valve
4. Vapor leaking past the fuel selector Valve O-rings from the pressurized cabin
5. Vapor in the line feeding the EDFP around the accessory case especially in a hot climb
6. Vapor anywhere else the fuel line runs next to a heat source, though less likely in the higher pressure areas. ( Anybody have a triple point chart for 100LL? Marv has a nice graph on 2/2/07 -- but no pressure axis or contour/family of curves... yet )

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