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RE: Europa-List: Static when Refuelling re Braid May 14, 2003 11:25:07

Subject: RE: Europa-List: Static when Refuelling re Braid May 14, 2003 11:25:07
From: Rob Housman <RobH@hyperionef.com>
Date: Wed, 14 May 2003 11:07:08

Let's not make this any more complicated than necessary folks.  What MUST be
done is to ground the aluminum filler neck to prevent sparking from the fuel
filler nozzle, and to install a conductor (the braid meets this requirement)
---From the filler neck to the bottom of the tank.  Nothing else matters.

See "How Do I Work Safely with Flammable and Combustible Liquids? (Static
Electricity)" at
http://www.ccohs.ca/oshanswers/prevention/flammable_static.html for an
excellent discussion of this, and near the bottom of the page there is
specific advice about filling non-conductive containers (like the Europa's
fuel tank).

Best regards,

Rob Housman
A070

-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com]On Behalf Of Brian
Rauchfuss - PCD
Subject: Re: Europa-List: Static when Refuelling re Braid May 14, 2003
11:25:07 am"

<brauchfu@pcocd2.intel.com>

<fillinger@ameritech.net>

> That would be braid dangling inside the tank, wired to electrical
> ground?  It won't do anything during refueling to suppress static
> charges, since fuel is essentially nonconductive.

It is because fuel has a low conductivity that the braid is required!  A
great deal of the static created in a nonconductive tank is due to the
turbulence of the non-conductive fluid as it flows down the refill pipe.
There is a very interesting experiment where distilled water is flowed
between two tanks that are insulated from each other.  A spark gap between
the tanks will start sparking as the charge builds.

The braid bleeds off the charge as the fuel flows around it - the close
contact between the two is required due to the low conductivity of fuel.
The main goal is to prevent any sparks from occuring near the filling point,
where the mixture can be low enough to support combustion - the center of
the
tank has too rich a mixture.

> FAA is clear about the lightning hazard problem with composite A/C.  The

Perhaps making the braid removable would solve the lightning problem?
Lightning is such bad news (as well as icing and severe turbulence which
tend
to go along with it) that I plan to stay far away from thunderstorms and
associated weather.

Brian




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