X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 04 Sep 2005 13:41:18 -0400 Message-ID: X-Original-Return-Path: Received: from sccrmhc11.comcast.net ([204.127.202.55] verified) by logan.com (CommuniGate Pro SMTP 5.0c2) with ESMTP id 710666 for lml@lancaironline.net; Sat, 03 Sep 2005 22:35:35 -0400 Received-SPF: none receiver=logan.com; client-ip=204.127.202.55; envelope-from=rpastusek@htii.com Received: from boblaptop2 (pcp08634725pcs.arlngt01.va.comcast.net[68.50.1.134]) by comcast.net (sccrmhc11) with SMTP id <2005090402345001100t5aare>; Sun, 4 Sep 2005 02:34:50 +0000 From: "Robert R Pastusek" X-Original-To: "Lancair Mailing List" Subject: RE: [LML] LIVPT outflow valve vacuum X-Original-Date: Sat, 3 Sep 2005 22:32:00 -0400 X-Original-Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0026_01C5B0D7.4CE30210" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_0026_01C5B0D7.4CE30210 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Barney Britton wrote... I am at the point of finally hooking up my pressurization outflow valve and notice that it seems to require vacuum to operate as well as the electrical connections. Does this valve really need vacuum to operate... Barney, The pressurization outflow valve does not require vacuum to operate. The vacuum, if available, pulls the modulator valve fully open when you select DUMP. The main downside of not using a vacuum source is an occasional surge in interior cabin pressure during high power settings when the aircraft is not pressurized. I considered installing the vacuum side of a door seal pump for this, but decided I could live with the surge to save some complexity and weight. Have since observed that this can be minimized by leaving the door seal uninflated until you are ready to pressurize. Bob Pastusek ------=_NextPart_000_0026_01C5B0D7.4CE30210 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Barney=20 Britton wrote...

I=20 am at the point of finally hooking up my pressurization outflow valve = and notice=20 that it seems to require vacuum to operate as well as the electrical=20 connections.  Does this valve really need vacuum to operate... 
 
Barney,
The pressurization outflow valve does not = require=20 vacuum to operate. The vacuum, if available, pulls the modulator valve = fully=20 open when you select DUMP. The main downside of not using a vacuum = source is an=20 occasional surge in interior cabin pressure during high power settings = when the=20 aircraft is not pressurized. I considered installing the vacuum side of = a door=20 seal pump for this, but decided I could live with the surge to save some = complexity and weight. Have since observed that this can be minimized by = leaving=20 the door seal uninflated until you are ready to=20 pressurize.
 
Bob Pastusek
 
------=_NextPart_000_0026_01C5B0D7.4CE30210--