X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 06 Sep 2013 11:31:40 -0400 Message-ID: X-Original-Return-Path: Received: from carbinge.com ([69.5.27.218] verified) by logan.com (CommuniGate Pro SMTP 6.0.6) with SMTP id 6456887 for lml@lancaironline.net; Fri, 06 Sep 2013 10:08:37 -0400 Received-SPF: none receiver=logan.com; client-ip=69.5.27.218; envelope-from=jbarrett@carbinge.com Received: (qmail 19275 invoked from network); 6 Sep 2013 14:08:03 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; h=X-Originating-IP:Reply-To:From:To:References:In-Reply-To:Subject:Date:Message-ID:MIME-Version:Content-Type:X-Mailer:Thread-Index:Content-Language; s=default; d=carbinge.com; b=M3H4aW4/OytNO76IuyB5qX/rUAzzT16Wi0wq3LDzaX9BgaaubEraFsShU+alQv3W9Khz6NUEGYXCMzytmXtE9X/KG0FdJAYxCT7Y4uzrJYYefd/DB1rPpARDwEJEVz8P+j3FUvveqJpp6nV1Ed/ni2b3eZwNmbTVFNs5nIYjiS4=; X-Originating-IP: [208.53.115.208] Reply-To: From: "John Barrett" X-Original-To: "'Lancair Mailing List'" References: In-Reply-To: Subject: RE: [LML] more on IVP pressurization X-Original-Date: Fri, 6 Sep 2013 07:08:02 -0700 X-Original-Message-ID: <006901ceab0a$80766af0$816340d0$@com> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_006A_01CEAACF.D41792F0" X-Mailer: Microsoft Office Outlook 12.0 Thread-Index: Ac6q9/HCbN7nI/8GRDyS8Pb3cQw+ngAEn65A Content-Language: en-us This is a multi-part message in MIME format. ------=_NextPart_000_006A_01CEAACF.D41792F0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Peter, Have been to 14K so far. I get about 11K cabin pressure. John From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of PETER WILLIAMS Sent: Friday, September 06, 2013 4:54 AM To: lml@lancaironline.net Subject: [LML] more on IVP pressurization john have you flown the airplane at altitude? after a bunch of work on sealing my 4P i have a 3,800' cabin at 17,500 with 32" and 2300rpm i have the altitude set at 1,000 feet; where it should be if i am returning to sea level peter > To: lml@lancaironline.net > Date: Wed, 4 Sep 2013 07:42:10 -0400 > From: 2thman1@gmail.com > Subject: [LML] IVP pressurization > > Having trouble getting my pressurization to work effectively. > I did my best to seal the pressure vessel but never got above .25 PSID with my 6 horse shop vac. Used both pressure and vacuum to check for leaks. No smoke but used a down feather and then a stethoscope with tympanic membrane removed. Outflow valve is covered during these tests. > > After lots of frustration i hired a guy who has built and/or pressurized about a dozen IVPs to come take a look. He determined using smoke that there were a couple of slight improvements to be made mostly in the wire bundles through the aft pressure bulkhead and after doing this he declared the vessel seal very good. > > So we deduced that maybe the shop vac is not as efficient at blowing air as I thought, but my flying experience with the aircraft is that it doesn't do much better than the .25 PSID in flight up to 14.5K ft. > > Wondering why there is inadequate pressurization with a good pressure vessel leads to thoughts of outflow valve problems. I bought the device with the kit in 1996 so it occurs to me the valve could be dirty or rubber diaphragm could be failing, etc. I removed the outflow valve yesterday and tried to examine the parts. i lubricated the mandrel that the poppet valve slides on with a very small spritz of LPS1 lubricant in case there was stiction there. I did notice that with the poppet valve manually moved to the furthest closed position the diaphragm still had somewhere around a 1/32" gap at the seating perimeters. Should the air pressure in flight fill that diaphragm to close the gap or does this indicate the valve needs servicing? > > Finally is there a way short of the manual dump switch to keep the system from pressurizing better than what I see by mismanaging the controller? Am I just setting the pressurization up wrong? Have only been up to 3,000 ft elevation airports, (KRDM) and lower - most at sea level. > > Thanks for any help. > > John Barrett > > Sent from my iPad > > -- > For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html ------=_NextPart_000_006A_01CEAACF.D41792F0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Peter,

 

Have been to 14K so far.  I get about 11K cabin = pressure.

 

John

 

From:= = Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of = PETER WILLIAMS
Sent: Friday, September 06, 2013 4:54 = AM
To: lml@lancaironline.net
Subject: [LML] more on = IVP pressurization

 

john

ha= ve you flown the airplane at altitude?

after a bunch of work on = sealing my 4P i have a 3,800' cabin at 17,500
with 32" and = 2300rpm
  i have the altitude set at 1,000 feet; where it should = be if i am returning to sea level

peter

<= p class=3DMsoNormal>> To: lml@lancaironline.net
> = Date: Wed, 4 Sep 2013 07:42:10 -0400
> From: 2thman1@gmail.com
> Subject: = [LML] IVP pressurization
>
> Having trouble getting my = pressurization to work effectively.
> I did my best to seal the = pressure vessel but never got above .25 PSID with my 6 horse shop vac. = Used both pressure and vacuum to check for leaks. No smoke but used a = down feather and then a stethoscope with tympanic membrane removed. = Outflow valve is covered during these tests.
>
> After lots = of frustration i hired a guy who has built and/or pressurized about a = dozen IVPs to come take a look. He determined using smoke that there = were a couple of slight improvements to be made mostly in the wire = bundles through the aft pressure bulkhead and after doing this he = declared the vessel seal very good.
>
> So we deduced that = maybe the shop vac is not as efficient at blowing air as I thought, but = my flying experience with the aircraft is that it doesn't do much better = than the .25 PSID in flight up to 14.5K ft.
>
> Wondering = why there is inadequate pressurization with a good pressure vessel leads = to thoughts of outflow valve problems. I bought the device with the kit = in 1996 so it occurs to me the valve could be dirty or rubber diaphragm = could be failing, etc. I removed the outflow valve yesterday and tried = to examine the parts. i lubricated the mandrel that the poppet valve = slides on with a very small spritz of LPS1 lubricant in case there was = stiction there. I did notice that with the poppet valve manually moved = to the furthest closed position the diaphragm still had somewhere around = a 1/32" gap at the seating perimeters. Should the air pressure in = flight fill that diaphragm to close the gap or does this indicate the = valve needs servicing?
>
> Finally is there a way short of = the manual dump switch to keep the system from pressurizing better than = what I see by mismanaging the controller? Am I just setting the = pressurization up wrong? Have only been up to 3,000 ft elevation = airports, (KRDM) and lower - most at sea level.
>
> Thanks = for any help.
>
> John Barrett
>
> Sent from = my iPad
>
> --
> For archives and unsub http://mail= .lancaironline.net:81/lists/lml/List.html

=
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