Thread: Canned petrol

I believe it is supposed to be related to building up a static charge by dragging your shoes on carpet.

I believe this has happened - as opposed to the whole mobile phone idea.

I'm guessing the travelling car with the wind "rubbing" over it can build up a charge - I have felt a small zap sometimes reaching for a door handle to get in a car, or brushing with my elbow.

I guess the "grounding" (literally) is meant to equalise the container potential with the ground potential ... I guess to avoid any spark when the nozzle goes into the container. I think that would be just as avoidable by placing your other hand on the vehicle/tray/container before and until the nozzle goes into the container. Holding the nozzle by the metal part if that feels safer.

Anyways ... I think that's approximately the thinking.

Cheers,
Paul

It is a fact of life that not all people have common sense.
I have seen people jump into the tray of the ute/truck to fill up can some even with a cigarette in their mouth, no grounding at all.
Not everybody use steel cans with a bare steel tray in their ute, some have carpet or rubber mats.
The rule was brought in when a petrol station in an Adelaide suburb blew up a few years ago.
I suppose one can't really blame the owners for not wanting their livelyhood to go up in flames.
One static spark and kaboomba
If you look at the petrol tank in your car or a built-in tank in a boat, they are both grounded to the chassis/hull.
In my book, that is a very small inconvenience for the customer and a big safeguard for the owner.
Diesel is different, it is not volatile.
Cheers
Wolffie

It is a rule for people who are not static aware.

Even the vehicle can hold a static charge, haven't you even been bitten when you got out & turned around to shut the door?

When you walk to the pump, you should ground yourself by touching the pump, then pick up the nozzle & walk back to the car & equalise the charge difference on the car by touching it with your other hand, (not the one with the nozzle) before you put the nozzle anywhere near the open fuel filler.
This helps stop the chance of a spark jumping between the nozzle & the filler pipe & possibly igniting fumes.

If you watch an aircraft or a service station being refuelled you will see the tanker driver first attach a 'grounding' or 'earth' strap/cable between the tanker & the object being refuelled. It doesn't have to be connected to ground, it just needs to be connected between the 2 items to equalise any static charge.

Static is funny stuff to understand so some seemingly strange rules need to be put in place.

The action of removing the fuel cans from the vehicle & placing them on the ground helps to reduce the chance of a spark.

If you are static aware enough to equalise the charge between the fuel can & the pump nozzle with your body then there is less chance of a spark but you have to remember to do it.

If it was diesel it wouldn't be an issue, but petrol is different.

My understanding is that you should always earth the container to ground as petrol produces significant static when poured between containers - that's why aircraft and fuel delivery tankers are grounded.

If you put the can/container on the ground where it has a direct earth, you have no issue. Being in/on a vehicle the tyres prevent this occuring.

It's not a nylon undies or static build up in the car issue.

Rob

I think it makes more sense when you consider that most people who bring a can in, have it in the boot of a car or the back of a hatch back or 4 wheel drive.
Regards

Don't the majority of the pumps have a picture on them showing that cans need to be filled by placing them on the ground first, along with the cross through the guy on the motorbike filling up his tank whilst sitting on his bike. I don't think that it is anything new .... although perhaps to those who don't often fill cans!

While I can appreciate that it's less likely that static will build up when the can is earthed on the ground, you have to ask yourself the fundamental question on all this.

What's the difference between a can on the back of a ute and a petrol tank attached to a ute?

None that I can see, both are isolated from earth by vehicle tyres, both have a small filler, both have petrol vapours in the free space, both can be zapped by a static charge from a person or phone.

Makes you wonder if it's a bit over the top in the real world.

PS I always put my cans on the ground because I feel safer that way

Rob

Originally Posted by nearnexus

While I can appreciate that it's less likely that static will build up when the can is earthed on the ground, you have to ask yourself the fundamental question on all this.

What's the difference between a can on the back of a ute and a petrol tank attached to a ute?

None that I can see, both are isolated from earth by vehicle tyres, both have a small filler, both have petrol vapours in the free space, both can be zapped by a static charge from a person or phone.

Makes you wonder if it's a bit over the top in the real world.

PS I always put my cans on the ground because I feel safer that way

Rob

The fuel tank in a vehicle or boat is earthed to the chassis or the hull of the boat, when refilling the boat the earth goes to the trailer,enough earthing to divert the static spark.

Quite apart from that, imagine knocking over a fuel can while it is in the boot, the back of a wagon or the tray of a ute.
Heaps and heaps of fumes, another car comes in and KOBOOMBA.
If the can is on the ground, it is easy to grab a hose and rinse the fuel off the surface, into the drains or wherever. Every fuel station now has a fuel spillage kit available.
Cheers
Wolffie

[QUOTE=Wolffie;1550381]The fuel tank in a vehicle or boat is earthed to the chassis or the hull of the boat, when refilling the boat the earth goes to the trailer,enough earthing to divert the static spark.

If that was the case, planes and fuel tankers wouldn't earth to ground.

Also, the fuel can resting on a metal ute tray would earth just as well/the same as a bolted in fuel tank, no difference. Static will easily jump an air gap to earth.

Rob

http://www.worksafe.vic.gov.au/__dat...le_liquids.pdf
http://www.workcover.nsw.gov.au/form...alert_2241.pdf

2 issues it would seem. 1 to minimise static and 2nd to minimise spillage and potential leakage / ignition

Also as it is a regulation / standard it does not have to be logical. It is a response to reduce the risk of some one filling 20 cans inside a landcruiser and lighting the place up again it would seem.

When you fill your vehicle you are conveniently earthed through the fuel nozzle touching the metal filling point. Static is generated by the flow of fluid through the hose so the whole hose is electrically conductive. Plus, YOU are holding the hose too and you are not very well insulated. Home-made or poorly designed ute trays who relocate the fill point with rubber hoses are a bit of a worry, factory approved trays USUALLY comply.

Portable containers (metal or plastic) are best filled on ground because even though the hose is conductive most containers are filled slowly without the nozzle touching so you can see the level rising, hence the possibility of static building up. And as previously said paint, carpet and tray liners etc will insulate the container.

Oh, diesel will also produce the same static charge as petrol; the difference is that diesel has a flash point of around 70+ plus, it is extremely difficult to ignite. Back in the days when we used to practice putting out diesel fires by setting fire to diesel (bloody environmentalists said it polluted too much!), we found the best way to set diesel alight was by....... pouring burning diesel on it.

As I said, some people have a carpet or a rubber mat in the bottom of the tray.
I also believe that the tanks in an airplane or a fuel tanker are a helluva lot bigger than the ones in a car.
Still reckon the biggest danger is knocking it over whilst it is somewhere in the car being filled.
Also reckon common sense is sadly lacking in most people, hence they have to be protected from themselves
Anyways, it is all academic, rules are there to be obeyed whether we agree with them or not.

Sorry chief, I replied to an earlier post before I saw yours.
"Oh, diesel will also produce the same static charge as petrol; the difference is that diesel has a flash point of around 70+ plus, it is extremely difficult to ignite. Back in the days when we used to practice putting out diesel fires by setting fire to diesel (bloody environmentalists said it polluted too much!), we found the best way to set diesel alight was by....... pouring burning diesel on it."
Fire drill in Coastguard, couldn't get the wretched diesel to burn as you just said.
Cheers
Wolffie.

Here's a classic case of static igniting fuel.

Gas Station Fire, Static Electricity Starts a Flash Fire. - YouTube

And it's a fuel tank in a car supposed adequately earthed according to earlier comments.


Rob

One thing that's only been loosely touched on by Chief Tiff is that when filling a container, on the ground, you should try and keep the pump nozzle in contact with the container to create a stronger earthing connection rather than holding the nozzle in the air so you can see how much you have in the container.

Like most things it's a rare chance for something to go wrong, but in this case, when it does...hooboy, you'll know it...for a split second.

There's this Mythbusters mini myth showing how static electricity is the primary culprit for fuel station ignitions and that mobile phones have pretty much nothing to do with it.
Mythbusters- Cell Phone Gas Station MiniMyth - YouTube
Full version: Mythbusters Cell Phone Destroys Gas Station (1/3) S01E02 - YouTube