X-Virus-Scanned: clean according to Sophos on Logan.com From: "Charlie England" Received: from mail-pa0-f47.google.com ([209.85.220.47] verified) by logan.com (CommuniGate Pro SMTP 6.0.10) with ESMTPS id 7240833 for flyrotary@lancaironline.net; Tue, 28 Oct 2014 14:57:55 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.220.47; envelope-from=ceengland7@gmail.com Received: by mail-pa0-f47.google.com with SMTP id kx10so1367723pab.34 for ; Tue, 28 Oct 2014 11:57:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:subject:references :in-reply-to:content-type; bh=TUKUwOVoAbZLPA41SX1TZ0115/PJk9wAwfgLWqKZv9M=; b=Z1Jl2gXGqMf176MbRD+DaDEHBkNatXJ+K1b1n+/m2iKouE0Yw7zBLTqI/8YORiI9PO KWwC2IFyms5FS4pTLhPkM8ktIe3lUg+GYYie1p97T+fi5KrOpDvfiKhFhL2UToR+lusP ye+kfH4mS8PY1vgNAPF5J2Rc2vr1YUhWUlTdulIz8XM8+ZyYkdDqUan7bwhUHXPAA4Vb 6RmP/Ft8hWpSjAtUDkNs1maBMHm7Nt7vQygLA2F/hnfPRfQCBiv+W3LTkqF+tmWT9S2M z5Ceb+FbsuaYIsojgXgKf61zP0sMA8ZuWO8YmfdRz2AJdfR5s1z60SJnuUj+PELGRmkL bfHg== X-Received: by 10.70.88.75 with SMTP id be11mr5624959pdb.32.1414522641681; Tue, 28 Oct 2014 11:57:21 -0700 (PDT) Return-Path: Received: from ?IPv6:2602:306:25fb:99:e511:72d4:a6a3:8e9d? ([2602:306:25fb:99:e511:72d4:a6a3:8e9d]) by mx.google.com with ESMTPSA id t13sm2333445pbs.4.2014.10.28.11.57.19 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 28 Oct 2014 11:57:20 -0700 (PDT) Message-ID: <544FE78D.8030300@gmail.com> Date: Tue, 28 Oct 2014 13:59:25 -0500 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: electric fuel selector valves References: In-Reply-To: Content-Type: multipart/alternative; boundary="------------030908010507050703060406" This is a multi-part message in MIME format. --------------030908010507050703060406 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Actually, if they'll survive in a truck, I doubt that a plane could hurt them (with proper installation). Some people are just paranoid about flexible fuel lines that aren't A/N Stainless braided. On the subject of backup fuel switching: If you have a ganged mechanical valve, why bother with the electric one? :-) Charlie On 10/28/2014 10:17 AM, Ernest Christley wrote: > Other than physical damage, which should be handled by proper, > stress-free mounting, the only failure mode I see is the valve getting > stuck on one tank or the other. This can be handled by tee-ing into > all supply and return lines, and connecting them with a ganged > mechanical on-off valve. If the electric valve gets stuck, pull the > mechanical ones on to allow fuel to crossover. Basically, creating a > Tee fitting into whichever port is open. > > I'm actually working on this for a Corvair installation, but this > forum is the only one I've found where an idea can be discussed on its > merits, instead of its compliance with standard practice. > > > On Tuesday, October 28, 2014 10:33 AM, Mitchell Williams > wrote: > > > http://products.pollakaftermarket.com/Asset/42-159%20IS_41-revdd.pdf > > > > On Mon, Oct 27, 2014 at 6:19 PM, Stephen Izett > > wrote: > > I stand corrected. I believe Charlie is correct. > Steve Izett > > >> On 28 Oct 2014, at 6:47 am, Charlie England >> > > wrote: >> >> On 10/27/2014 4:55 PM, Ernest Christley wrote: >>> This is the type that I'm referring to: >>> >>> http://products.pollakaftermarket.com/item/fuel-selector-valves/light-truck-6-port-motor-driven-valve/42-302 >>> >>> >>> On Monday, October 27, 2014 5:50 PM, Ernest Christley >>> >>> wrote: >>> >>> >>> Is anyone familiar with electric fuel selector valves as used in >>> automotive applications. I'm trying to figure out how they >>> operate. Do they select one line when power is applied to a >>> solenoid type plunger, and then the other line is selected when >>> power isn't applied? Or does a pulse of power switch them back >>> and forth? If they maintain the currently selected tank when >>> power is absent, it seems to me that this could remove fuel >>> lines and a leak prone selector valve from a lot of cockpits. >>> Furthermore, the 6 port models look like they could be plumbed >>> easily to handle return lines. >>> >>> >>> >> The ones I've seen actually use a motor to move the valve (think >> screw jack), so they will remain in last position. Reading your >> linked item indicates that it works the same way. >> >> 'Traditional' engine guys have avoided them in the past because >> they're plastic and they require power (and they are an >> automotive product, so they can't be reliable ;-) ). They are >> probably worth considering, but I'm seriously looking at >> switching to in-tank turbine pumps with automotive style PWM >> control; no return line needed. Then tank selection would be with >> a switch on the panel instead of a valve. Downside is that for >> total redundancy, I'd need 2 pumps in each tank. They are dirt >> cheap (<$20 each), but controllers are around $75 ea and >> switching gets pretty elaborate if there are more than 2 tanks. >> >> Charlie > > > > > -- > Mitchell Williams OKPE, ATP/CFI/A&P/IA www.chickashawings.com > > *_of shadow and ash_* http://www.amazon.com/dp/B009KZGVQS > > > --------------030908010507050703060406 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit
Actually, if they'll survive in a truck, I doubt that a plane could hurt them (with proper installation). Some people are just paranoid about flexible fuel lines that aren't A/N Stainless braided.

On the subject of backup fuel switching: If you have a ganged mechanical valve, why bother with the electric one? :-)

Charlie

On 10/28/2014 10:17 AM, Ernest Christley wrote:
Other than physical damage, which should be handled by proper, stress-free mounting, the only failure mode I see is the valve getting stuck on one tank or the other.  This can be handled by tee-ing into all supply and return lines, and connecting them with a ganged mechanical on-off valve.  If the electric valve gets stuck, pull the mechanical ones on to allow fuel to crossover.  Basically, creating a Tee fitting into whichever port is open. 

I'm actually working on this for a Corvair installation, but this forum is the only one I've found where an idea can be discussed on its merits, instead of its compliance with standard practice.


On Tuesday, October 28, 2014 10:33 AM, Mitchell Williams <flyrotary@lancaironline.net> wrote:



On Mon, Oct 27, 2014 at 6:19 PM, Stephen Izett <flyrotary@lancaironline.net> wrote:
I stand corrected. I believe Charlie is correct.
Steve Izett


On 28 Oct 2014, at 6:47 am, Charlie England <flyrotary@lancaironline.net> wrote:

On 10/27/2014 4:55 PM, Ernest Christley wrote:
This is the type that I'm referring to:



On Monday, October 27, 2014 5:50 PM, Ernest Christley <flyrotary@lancaironline.net> wrote:


Is anyone familiar with electric fuel selector valves as used in automotive applications.  I'm trying to figure out how they operate.  Do they select one line when power is applied to a solenoid type plunger, and then the other line is selected when power isn't applied?  Or does a pulse of power switch them back and forth?  If they maintain the currently selected tank when power is absent, it seems to me that this could remove fuel lines and a leak prone selector valve from a lot of cockpits.  Furthermore, the 6 port models look like they could be plumbed easily to handle return lines.



The ones I've seen actually use a motor to move the valve (think screw jack), so they will remain in last position. Reading your linked item indicates that it works the same way.

'Traditional' engine guys have avoided them in the past because they're plastic and they require power (and they are an automotive product, so they can't be reliable ;-)  ). They are probably worth considering, but I'm seriously looking at switching to in-tank turbine pumps with automotive style PWM control; no return line needed. Then tank selection would be with a switch on the panel instead of a valve. Downside is that for total redundancy, I'd need 2 pumps in each tank. They are dirt cheap (<$20 each), but controllers are around $75 ea and switching gets pretty elaborate if there are more than 2 tanks.

Charlie




--
Mitchell Williams OKPE, ATP/CFI/A&P/IA   www.chickashawings.com
of shadow and ash http://www.amazon.com/dp/B009KZGVQS




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