David's Build Thread

[Stot]

Originally Posted by CTWV50

Surely if you earth the tank to the body when fuel causes a path of least resistance between the tank and the live wire in the tank the pump and/or sender will stop working and probably blow a fuse??

Petrol has very little electrical conductivity. Consider that the fuel level sender is offen a bare resistance coil dipped right in the petrol and it doesnt affect it. Also given that the fuel is wrapped up in metal, the fuel its self will never be the path of least resistance. AFAIK most fuel tanks are earthed.

edit: Found this in a Fire Brigade, Fire Safety leaflet.

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.

Cheers
Stot

[CTWV50]

Thanks for that david. And thanks for clearing up the question of petrol condutivity everyone! Haha.

[flyerncle]

Have seen films of petrol tanker explosion caused through static when I did an ADR course, Guy was blown from top of tanker when answering phone,a women slides across seat to get purse and touches nozzle and bang nice fire.

Moral of story,dont wear nylon and earth the tank.


Sender unit resistor is insulated from body of tank otherwise A,it would not work and B it would short and blow fuse.

[Eternal]

LOL thankd David you are my 200th sub on youtube! Will have to send you a Mars bar or something =P

[Davidbolam]

Originally Posted by Eternal

LOL thankd David you are my 200th sub on youtube! Will have to send you a Mars bar or something =P

I've also noticed a new roadster on there. its only been on for 2 weeks and is racing an m3 around a track. Looks like spuds car.

Does anyone know who's it is??
David

[mark]

Definitely spuds car

Seemed to be doing ok too, although the m3 seemed more interested in going sideways than fast

[flyerncle]

Had a ride in Spuds car at Teeside,well sorted and handy motor,defo better than beemer.