Fuel tank earth?

PostPost by: Tonyw » Mon Apr 11, 2011 2:03 pm

Hi all,

I have just fitted my fuel tank and thought it might be a good idea to earth the tank to avoid any possibility of a static "spark" igniting the fuel what is the consensus? can it do any harm?

Regards,

Tonyw
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PostPost by: john.p.clegg » Mon Apr 11, 2011 2:39 pm

Tony

There should be an earth already (albeit a little one) for your sender..

John :wink:
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PostPost by: rdssdi » Wed Apr 13, 2011 12:04 am

I used earthing braid to be certain my tank, tank brackets and filler neck at fender (wing) were all grounded.

You can see this in the photos. I know the braid is large. It was the braid I had and works well albeit a bit of overkill.

Bob
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tankgnd1.jpg and
tankgnd2.jpg and
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PostPost by: rdssdi » Wed Apr 13, 2011 12:05 am

In photo 2 it is difficult to see but the earthing braid terminates at the filler neck assembly.

Bob
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PostPost by: Tonyw » Wed Apr 13, 2011 6:36 am

Thanks Guy's,

I will add a separate earth just to be sure.

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PostPost by: Emma-Knight » Thu Mar 15, 2012 3:51 pm

What purpose is the earth connection. For fueling or during drive. For fueling, question is - earth in relation to what? :shock: As far as I remember, planes need a ground line between plane and filling system. Plane stands on isolating tires as does the car. So an earthing strap will connect just a little more mass and either negative or positive batterie....

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PostPost by: Steve G » Thu Mar 15, 2012 4:55 pm

Emma-Knight wrote:What purpose is the earth connection. For fueling or during drive. For fueling, question is - earth in relation to what? :shock: As far as I remember, planes need a ground line between plane and filling system. Plane stands on isolating tires as does the car. So an earthing strap will connect just a little more mass and either negative or positive batterie....

Anna (needs to fix the windscreenframe instead of posting) :roll:


The earth for the fuel tank is just to earth it to something large and metallic, i.e. the chassis, it is not earthing to the earth via a trailing earth strap, those things are to discharge static so you don't get a shock getting out of the car.

margaret wrote:some weird stuff


I've found the best way to save fuel is to lose the key for the fuel filler cap...
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PostPost by: ardee_selby » Thu Mar 15, 2012 5:12 pm

Emma-Knight wrote:What purpose is the earth connection. For fueling or during drive.


Earthing of filler neck more important?

Quote from: http://www.westyorksfire.gov.uk/uploads ... bb067e.pdf

"3.2.2 Petrol Engined Vehicles
Gasoline vapours contained within the fuel tanks of road vehicles are generally too rich to ignite. However, there is a zone near the tank filler cap, which may be in the flammable range when the cap is removed. During fuelling, flammable atmospheres may exist externally around the filler orifice. Therefore the possibility of an ignition from electrostatic discharge has to be considered.
The flow rates and hose diameters used at service stations are usually small enough to ensure that dangerous levels of static charge are not built up in either the vehicle's fuel tank (provided the design is such that it is not highly insulated from the vehicle body) or on the surface of the filling hose. There is the possibility however that an insulated conductor involved in the operation, such as the filling nozzle, the vehicle itself, an insulated filler neck on the vehicle tank, or the person doing the filling, could accumulate a static charge. Any of these could produce a spark in the flammable zone around the filling inlet and cause an ignition."


Richard
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PostPost by: bob_rich » Fri Mar 16, 2012 8:01 pm

Hi Folks

The use of the term earthing can be confusing. I have connected the fuel filler and fuel tank firmly to the chassis on my +2S 130. I just felt that it would be good practice to have all conductive metal parts in the fuel filling system at the same electrical potential. i.e. car chassis potential.

cheers

Bob
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PostPost by: simonknee » Thu Mar 29, 2012 6:31 pm

Emma-Knight wrote:... Plane stands on isolating tires</a> as does the car.


Common misconception. Car tyres may be rubber but they are loaded with carbon - that's why they are black. They are very conductive! Take you multimeter and test it out. Test between an earth point in the car and the other on the tyre. You will be surprised at how low the impedance is.

Those dangling earth things people attached back in the day were pure snake oil.

Simon

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PostPost by: jk952 » Fri Mar 30, 2012 1:12 am

I vaguely recall the aircraft grounding before refueling has more to do with large surface area metal object wooshing through air having a greater tendancy to pick up a static charge...
small fiberglass object wooshing not quite so fast (unless compared to a cessna 150) less likely so :D :D

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