I agree with Tony. Check valves are not called for in the manual and I
don't think they are necessary.
I have just finished installing an EI 5L flowmeter and with one pump running
and the return transducer disconnected, the circulating flow was over 75
litres/hour (engine not running) - it would appear any reverse flow through
the inactive pump is negligible.
regards,
Mike.
----- Original Message -----
From: "Tony S. Krzyzewski" <tonyk@kaon.co.nz>
Subject: RE: Europa-List: Mounting fuel pumps
>
>
> So make sure you account
> > for this and install some check valves.
>
> > I noted that too but did not test how much pressure loss results. The
>
> Rotax 914 manual states check valves aren't necessary.
>
> I think you'll find that just about every 914 installation on the planet
> uses the Rotax supplied pumps without check valves.
>
> Considering that you normally fly the 914 with only one of the pumps
> running, if the backflow through the failed/turned off pump was a
> problem there wouldn't be any airborne 914 powered aircraft.
>
> Tony
>
>
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