REFLECTOR: Electric fuel valves

[Jim Agnew]

Actually Jim these valves take about 250 milliseconds to transfer position and
no power after the transfer.  So unless you have a total electric failure you
have time to change them.  Since I have a small backup battery a total power
failure would still allow me to switch.

Jim

--- Jim Sower <canarder at frontiernet.net> wrote:

> That's true.  I would have preferred solenoid valves that would fail 
> open.  However, as a practical matter, with the valves powered by the 
> main buss, if you can't move the valve one of two things are happening:  
> a) you have a serious electrical failure and are heading for the nearest 
> airport you can land at, and should have more than sufficient fuel in 
> the tank that IS transferring (it was, after all, the one with too much 
> fuel in it) to get you there;  or  b) the valve failed closed and would 
> not open when you saw your tanks were even again, so now you have half 
> as much fuel as you thought, which should be more than adequate to get 
> to a decent en route alternate.
> So in the cosmic scheme of things, it really doesn't matter ... Jim S.
> 
> KeithHallsten wrote:
> 
> >No, these need power to move, so they fail in the last position selected.
> >This is in contrast to typical solenoid valves, which are spring loaded to
> >one position (either open or closed) and need continuous power to phold them
> >in the other position.
> >
> >Keith Hallsten
> >
> >
> >----- Original Message ----- 
> >From: "Scott Derrick" <scott at tnstaafl.net>
> >To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org>
> >Sent: Friday, October 29, 2004 4:33 PM
> >Subject: Re: REFLECTOR: Uneven fuel draw
> >
> >
> >  
> >
> >>jim,
> >>
> >>Are you saying these are fail closed?
> >>
> >>Scott
> >>
> >>At 10:59 AM 10/29/2004, you wrote:
> >>    
> >>
> >>>Don't recall.  They are from JCW and are fuel tank selector valves.  They
> >>>have supply and return for two tanks.  That's SIX nipples.  I only used
> >>>two and plugged the other four.  I used them because the guy who sold
> >>>      
> >>>
> >them
> >  
> >
> >>>to me made me an offer I couldn't refuse.  I was seriously considering
> >>>manual valves from Wicks for about $10 but wire is easier to string than
> >>>cable.  There used to be solenoid valves that failed open at JCW but
> >>>they're not there any more.
> >>>Think about the manual valves too .... Jim S.
> >>>
> >>>
> >>><mailto:PVTPIL8 at aol.com>PVTPIL8 at aol.com wrote:
> >>>      
> >>>
> >>>>Canarder Thanks for the info what were the valve part numbers.
> >>>>Steve
> >>>>
> >>>>
> >>>>        
> >>>>
> 
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=====
James F. Agnew
Jim_Agnew_2 at Yahoo.Com
Tampa, FL
Velocity 173 Elite Aircraft Completed & Flying