X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 18 May 2011 15:04:57 -0400 Message-ID: X-Original-Return-Path: Received: from elasmtp-scoter.atl.sa.earthlink.net ([209.86.89.67] verified) by logan.com (CommuniGate Pro SMTP 5.4c3j) with ESMTP id 4987582 for lml@lancaironline.net; Wed, 18 May 2011 12:16:17 -0400 Received-SPF: none receiver=logan.com; client-ip=209.86.89.67; envelope-from=colyncase@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=hs/2fDwYpuTDb+v0sZhBeFlrlrbpzsqTe9LI26D7HIcpoV4QLua2czssQn6srJuP; h=Received:From:Mime-Version:Content-Type:Subject:Date:In-Reply-To:To:References:Message-Id:X-Mailer:X-ELNK-Trace:X-Originating-IP; Received: from [216.57.118.194] (helo=[192.168.1.131]) by elasmtp-scoter.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1QMjPR-00055q-6f for lml@lancaironline.net; Wed, 18 May 2011 12:15:41 -0400 From: Colyn Case Mime-Version: 1.0 (Apple Message framework v1082) Content-Type: multipart/alternative; boundary=Apple-Mail-241-1010626417 Subject: Re: [LML] Fuel restriction or air? X-Original-Date: Wed, 18 May 2011 12:15:40 -0400 In-Reply-To: X-Original-To: "Lancair Mailing List" References: X-Original-Message-Id: <5ECFB696-F7E8-4254-A334-D04F81ED4089@earthlink.net> X-Mailer: Apple Mail (2.1082) X-ELNK-Trace: 63d5d3452847f8b1d6dd28457998182d7e972de0d01da940cb5ccb135bb04ce6147580b43a91a57e350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 216.57.118.194 --Apple-Mail-241-1010626417 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii that's radical. do you have the specs on the check valves for how much = pressure it takes to get them to reverse flow? On May 18, 2011, at 7:43 AM, Bill Hannahan wrote: > =20 > {Did you verify the fuel vents are working properly? ....and that = the check valves on the vents are oriented correctly?} > =20 > There should be no check valves on vent lines. If you take off at sea = level with a wing tank at atmospheric pressure, 14.7 psia trapped by a = check valve, and climb to 18,000 feet, static pressure 7.35 psia, the = differential pressure on the tank will be 7.35 psi, 1,058 pounds per = square foot trying to rip the skins off the spar and ribs. > =20 > Vent lines must be free flowing both directions. > =20 > Regards, > Bill Hannahan >=20 > wfhannahan@yahoo.com >=20 --Apple-Mail-241-1010626417 Content-Transfer-Encoding: 7bit Content-Type: text/html; charset=us-ascii that's radical.  do you have the specs on the check valves for how much pressure it takes to get them to reverse flow?

On May 18, 2011, at 7:43 AM, Bill Hannahan wrote:

 

{Did you verify the fuel vents are working properly?   ....and that the check valves on the vents are oriented correctly?}

 

There should be no check valves on vent lines. If you take off at sea level with a wing tank at atmospheric pressure, 14.7 psia trapped by a check valve, and climb to 18,000 feet, static pressure 7.35 psia, the differential pressure on the tank will be 7.35 psi, 1,058 pounds per square foot trying to rip the skins off the spar and ribs.

 

Vent lines must be free flowing both directions.

 

Regards,
Bill Hannahan


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