Hi Raimo
Thx. for your elaboration.
From what you wrote, you must have a 912S?
The 914 returns a lot of fuel to the tank compared to the 912S. By
returning fuel to the top of the tank, I think I remember reading it may
not be a great idea to let fuel (especially auto fuel) cascade as I think
it may somehow accelerate spoiling the fuel? Did you ever hear of this? I
suppose could put a dip tube to the bottom of the tank to prevent this?
On the 914 you don't want much in the way of back pressure as it can
cause problems with proper functioning of the fuel pressure
regulator.
Ron Parigoris
Hi Ron,
>
> I try to elaborate this a bit:
>
> Think what happen if you will get a leak to this line. Return fuel
is then
> coming out from engine as well as direct from the tank by
gravity.
> Remember €“ if installed as per manual
€“ a fuel return line is
> connected to the reserve side bottom of the tank.
>
> Even worse scenario: during succesful forced landing your ac will
suffer
> minor damages to the fire wall etc. Before landing you have closed
as per
> POH your fuel valve but you have no valve in the fuel return line.
If it
> is broken your tank will go empty under you. Maybe you are not able
to
> escape in time. How is then sitting as jammed in the ac, listening
fuel
> splitting out and waiting the possible flames?
>
> Of course it is possible to have also a manual fuel valve in the
return
> line also. Intead of that one-way-valve is automatic and works well
if
> located as close as possible from the tank.
>
> Before installing my one-way-valve I closed the entire fuel return
line
> and I did not noticed any difference (there is a risk for a vapour
lock
> /fire upp engine difficulties when semi warm and reserve side of the
tank
> is then also not refreshed ie. always full).
>
> If I were building now, I would like to instal the fuel return line
joint
> to the top of the tank instead of the bottom of it.
Thats bad only if
> you are inverted...and damaging the ac same time.
>
> How was my elaboration?
>
>
>
> Cheers, Raimo Toivio
>
>
>
> Europa XS Mono OH-XRT #417
>
> Updated flight hours /landings: 376 /604
>
> (no damaged props so far)
>
> 37500 Lempaala
> FINLAND
>
> p +358-3-3753 777
> f +358-3-3753 100
>
> www.rwm.fi
>
>
>
>
>
>
From: rparigor@suffolk.lib.ny.us
> Sent: Friday, September 06, 2013 5:21 AM
> To: Europa
> Subject: Re: Europa-List: Fuel filters
>
> Hi Raimo
>
> You mentioned:
>
> Notice:
>
> - Adding one-way-valve to the fuel return line
> (idea by Frans Veldman) is a great must (and
> mandatory at least for me).
> Can you elaborate a little on why you might want to put a
one-way-valve on
> the fuel return line? Is this for a 914 fuel system?
>
> Thx.
>
> Ron Parigoris
>
>
>
>
>
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