> I would go for the aluminium elbow at the bottom of the XS filler
> moulding, get some coarse mesh attached at the lower end, then
> ground the elbow with every other metal bit, including of course
> the filler cap.
I'm unclear what problem this is solving. Static generated in the fill
pipe? The Fiberglass Tank and Pipe Institute say that static charge in
nonconductive pipe is all about velocity, with fuel flow of 12 ft/sec is
a typical threshold. In the Europa Mk 1 filler pipe, that requires 120
gal/minute! But such velocity can be created by whirlpooling fuel down
a plastic funnel, and thus refiners say don't ever do that. Seems also
the mesh will only dissipate static that the mesh itself is creating.
I now can't even find support that grounding the metal filler cap ass'y
does much of anything, and it may even be more hazardous when fueling
---From a gas can, should the A/C be grounded to earth. The above
Institute, discussing filling above-ground, nonconductive tanks says:
"The addition of grounding systems (e. g., grounding rods) will not
reduce the hazard associated with electrostatic...." The hazard occurs
if the can's spout is allowed to come out of contact with the metal.
Were the metal not earthed, there's less hazard if the fueler is
standing on a paved surface.
I found the natural gas industry says the same thing. The static charge
on the inside wall in underground polyethylene gas mains is a serious
problem when servicing the pipe. A periodic metal connection in the
buried pipe does nothing, and that's not how it is dealt with nor
adaptable to an airplane.
Regards,
Fred F.
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