X-Virus-Scanned: clean according to Sophos on Logan.com From: "Charlie England" Received: from mail-pd0-f170.google.com ([209.85.192.170] verified) by logan.com (CommuniGate Pro SMTP 6.0.10) with ESMTPS id 7239087 for flyrotary@lancaironline.net; Mon, 27 Oct 2014 18:46:00 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.192.170; envelope-from=ceengland7@gmail.com Received: by mail-pd0-f170.google.com with SMTP id z10so6495228pdj.15 for ; Mon, 27 Oct 2014 15:45:27 -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=c7JDXoEpEg5BfkyzBeTUSiXwVX/zq6GJQz87Cs32isk=; b=uL2Jfc8bQxHnQVaX6qbwTkThegPHeKhI3QHcOJQjST1sYCH9QH76KgVNyeRVoYc76B RzY0Z/GKtmkVdCuiMtXuAfoq0QtofWx0PRStNkm5wTITKJP/IkiNnBjbM+ysWei+RaAO cCrvdXGoxiEPW/q4w5vhlfyzCG2DU2rgqUyJqs1RQHFz1mSUCIDJImmZ9cvc2CAd6/RE zfyg85J84X0ZgOOjz2wIjh+N/sj3Y/OJeaeFkPF7ZJxf64MrZ0YYy+esOA4yjkyZBsve lwoF5hjJ9vR+8KicaxPYLTzFzz2ORVrcCW4gQPdeb904QNtVkm1g0efBJbOdTISLRGet hLiA== X-Received: by 10.70.51.195 with SMTP id m3mr26849604pdo.27.1414449927599; Mon, 27 Oct 2014 15:45:27 -0700 (PDT) Return-Path: Received: from ?IPv6:2602:306:25fb:99:c8cd:dc65:37e:265f? ([2602:306:25fb:99:c8cd:dc65:37e:265f]) by mx.google.com with ESMTPSA id xy3sm11765756pbb.38.2014.10.27.15.45.25 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 27 Oct 2014 15:45:26 -0700 (PDT) Message-ID: <544ECB84.2000807@gmail.com> Date: Mon, 27 Oct 2014 17:47:32 -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="------------070800030609050009060704" This is a multi-part message in MIME format. --------------070800030609050009060704 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit 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 --------------070800030609050009060704 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit
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
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