Filling fuel cans on vehicle

[patrick_g]

I have a 12' ground wire on the tanks with a clip. Would running the wire from transfer tank to the pump make more sense than running it to frame of truck or is both required? Seems to me that if Transfer tank has same ground as pump it really would not need connection to truck.

Am I mistaken though in that the built-in fuel tank only has a "bond" to vehicle and that if transfer tank is bonded to frame it has approx. same risk of creating a static spark when bringing nozzle to filler as the built-in tank?

Thanks for the input. As you can tell "electricity" is not one of my strenths!

Tim

Tim, connecting the tank's wire to the station's pump is way better than connecting it to the truck. If the tank is insulated from the truck like with spray-on bed liner, paint, or... then an additional connection from tank to truck is a good idea.

Pat

 

[chapmx]

Thx Pat.

I will do that from now on. Until recently I have only had a single portable tank which I used for Diesel. It has a 12' ground wire which I would connect via its alligator clip to bare part of frame prior to filling thinking that it is giving me the same grounding as the "built-in" fuel tank. Since I only used it for diesel I was never real concerned as diesel is not nearly as volatile as gas. Recently got the second portable tank for gas and thought I should verify the best way to minimize the risk of static. From now on I will connect the grounding wire's alligator clip to pump prior to filling assuming there is a "good" place to attach it! Guess it can be attached directly to metal part of nozzle handle as nozzle is/should be grounded back to pump via cable ...

Thx. Again.

Tim

 

[bcp]

I seem to recall long ago fuel trucks had a cable or strap of some sort that dragged the ground all the time. I haven't noticed one in years.

Maybe I'm just not paying attention any more.

Bruce

 

[patrick_g]

Thx Pat.

I will do that from now on. Until recently I have only had a single portable tank which I used for Diesel. It has a 12' ground wire which I would connect via its alligator clip to bare part of frame prior to filling thinking that it is giving me the same grounding as the "built-in" fuel tank. Since I only used it for diesel I was never real concerned as diesel is not nearly as volatile as gas. Recently got the second portable tank for gas and thought I should verify the best way to minimize the risk of static. From now on I will connect the grounding wire's alligator clip to pump prior to filling assuming there is a "good" place to attach it! Guess it can be attached directly to metal part of nozzle handle as nozzle is/should be grounded back to pump via cable ...

Thx. Again.

Tim

Tim "grounding" the portable tank to the truck frame DOES give you the same grounding the built-in tank has which is NONE AT ALL.

Most vehicles are on rubber tires that are pretty fair insulators so the truck is NOT GROUNDED nor something to ground something else to for static reduction.

It is all about potential difference and avoiding there being any. If you electrically connect everything in the delivery system together then everything is at the same potential and there will be no static sparks. It is good that your built-in tank is bonded to the vehicle frame but to prevent sparks between the nozzle and the vehicle you need to ensure the nozzle and your vehicle are at the same potential. Your ground wire to the pump or the nozzle does that.

Pat

NOTE FOR BCP:

Tanker trucks and such used to have grounding chains that dragged the pavement making a few sparks now and then. Haven't seen those for a long time.

 

[Steve C]

Ummm...This is why I said that even filling on the ground, I touch the nozzle to the can before turning on the pump. It doesn't matter at that point if the can is on the ground, bed, or moon, both objects have the same ground.

It's real easy to point a finger, read a label, and say you're wrong. I have a degree in electronics and know that when 2 objects make contact, it doesn't matter where they are, they share the same ground.

You are very wrong.

To be considered grounded we have to drive 2 copper rods 6 foot into the earth and connect them together to get a low enough impedence to current flow for it to be considered grounded in our soil conditions. I know this because I just installed an electrical service to my house.

While pumping gas into a plastic can the charge can build up because of the gas sloshing on the plastic and the free fall of the gas through the air in the head space of the can will also generate a charge. While the fuel is flowing the danger is slight because the charge can blead back through the liquid to the nozzle that is grounded. As soon as the flow stops, all bets are off. If there is enough of a charge in the liquid it will try to go to ground. Its only path is to jump through the now vapor filled head space of the can to the nozzle on the pump.

I have a degree in nothing, however I have 35 years experience as a mechanical designer in the chemical and nuclear industry. Solids and liquids moving through air, pipe and hose will build up a charge and if the charge isn't bled off to ground without the generation of a spark bad things can happen.

Everything in a chemical plant is grounded, and the impedence of the grounds are checked to make sure that corrosion and soil conditions haven't degraded them.

Several large ships and barges have been lost to static discharge during loading and unloading operations. We saw the results of many of these accidents in our safety training films. If a metal ship sitting in water isn't grounded enough to prevent an explosion it is unlikely that a plastic container sitting on dry asphalt or concrete has much of a chance of bleeding off an electrical charge to ground.

It has been suggested that it was static electricity that leveled a fire works factory near my house in Hillsdale several years ago. The explosion was so great that the only thing left of the factory was the cement slab. The force of the blast excavated a shallow wide trench completely around the perimeter of the slab. All the employees were killed. The attached photo shows whatwas left of the factory.





Take a look at these photo's. 600 people died possibly because somebody didn't understand this principle....

It has been suggested that static discharge caused this, but we will never know for sure.


Texas City Disaster Pictures

 

[patrick_g]

Steve, you forgot to mention that setting ther cans on "the ground" does not necessarily ground them, especially if the "ground" is asphalt or dry concrete.

Pat

 

[Steve C]

Steve, you forgot to mention that setting ther cans on "the ground" does not necessarily ground them, especially if the "ground" is asphalt or dry concrete.

Pat

opps

thanks you are right...I just edited my post to reflect that...

 

[patrick_g]

opps

thanks you are right...I just edited my post to reflect that...

Steve, Glad I could help.

Over and over again we see the equivalent of folks promulgating information based on a very limited sample size with no consideration for reality. It is what I call the "crossing the street syndrome" where someone crosses the street without looking either way and because they get away with it, thereafter they claim it to be OK and maybe recommend it to others. Of course, it is risky behavior known to sometimes result in getting run over but what the heck, little Joe did it several times and nothing bad happened.

Pat

 

[Steve C]

Steve, Glad I could help.

Over and over again we see the equivalent of folks promulgating information based on a very limited sample size with no consideration for reality. It is what I call the "crossing the street syndrome" where someone crosses the street without looking either way and because they get away with it, thereafter they claim it to be OK and maybe recommend it to others. Of course, it is risky behavior known to sometimes result in getting run over but what the heck, little Joe did it several times and nothing bad happened.

Pat

Very good point.

I am sure that many of us have filled gas cans that were sitting on a tailgate or flat bed trailer, especially in the winter when we don't want to set them down in the melting slop of snow and ice. I have done it and I have seen people do it, and I have never seen one catch on fire. You could probably do it hundreds of times without a problem, maybee even an entire lifetime.

However when that one in a million event happens, I think most people would rather have the can sitting on the ground while on fire instead of in their vehicle. The only way to do it as safe as possible is to set the can on the ground.

When investigating the explosion at the fire works factory the investigators came to the conclusion that it was a static spark caused when the owner opened the door to the factory after getting out of his car. It was at that moment that it blew up. He was blown away from the building and was burned over 85% of his body. He died a short time later. He had got out of his car and opened that door thousands of times before without a problem.

 

[LBrown59]

Very good point.

I am sure that many of us have filled gas cans that were sitting on a tailgate or flat bed trailer, especially in the winter when we don't want to set them down in the melting slop of snow and ice. I have done it and I have seen people do it, and I have never seen one catch on fire. You could probably do it hundreds of times without a problem, maybee even an entire lifetime.

However when that one in a million event happens, I think most people would rather have the can sitting on the ground while on fire instead of in their vehicle. The only way to do it as safe as possible is to set the can on the ground.

When investigating the explosion at the fire works factory the investigators came to the conclusion that it was a static spark caused when the owner opened the door to the factory after getting out of his car. It was at that moment that it blew up. He was blown away from the building and was burned over 85% of his body. He died a short time later. He had got out of his car and opened that door thousands of times before without a problem.

How do you do that with a 30 or55 gallon drum or tank.?