Al Gietzen wrote:
>
> My simple approach is to use a metal chain, which serves as cap retainer,
> which hangs from the metal cap flange into the fuel, back to the cap.
> Contacting the end of the hose to cap/cap flange prior to removal takes car
> of any residual.  Maintaining contact between the hose and the flange
> (keeping the cap chain, or cable, hanging into the fuel) keeps fuel and hose
> at the same potential.
>
> 
Al, you're giving me the heebee-jeebees here.

The problem is that the can and fuel in the tank may already have a
differential charge built up.  Then you may be getting an invisibly
small spark connecting the can to the chain in the tank.  The spark
would have to be at just the right place to get a fuel-air mixture to
ignite, so chances of bad things happening are extremely low.  But such
an easily remediated exposure.

Get an ESD wrist strap from RadioShack or other electronic supplier. 
For those who don't know, these are bungee straps woven with a
conductive (carbon?) fiber.  They have a clip which connects to a coiled
wire lead, terminated by an alligator clip.  The wire has a large value
resistor in it.  You attach the alligator clip to what you want to be
grounded to, and then the static potential energy drains through the
wire.  The difference from just letting a chain contact is that the
charge drains at a controlled rate.  It is slow enough to eliminate the
spark.

Get a metal can and cinch one of these straps around the neck onto
exposed metal.  Now you have your grounding wire that will extend and
collapse like a telephone cord, and eliminates one more avenue of disaster.

http://www.ernest.isa-geek.org

 

Back in the olden days when I fueled aircraft, we had a grounding plug attached to the fuel nozzle, that was to be plugged into a receptical next to the filling port on each aircraft (Navy) and unplugged only after the cover or cap had been replaced on that tank. Even the oil truck had this system. Nobody has seen the oil truck in a while? This plug was attached (a fat wire) to the stainless braid inside the fuel hose covering (outside layer). I don't know how or if the truck was grounded. But we never had a problem, and I never heard of any fueling problems with that system. 

 

This system does not sound so complex that it could not be replicated by anyone, on any style of fueling system.  

 

Lynn E. Hanover