Filling fuel cans on vehicle

[Transit]

You're all right about your experiences with static electric, it's not a one size fits all phonon. It takes about 50,000 volts to jump a one inch gap and that is highly dependent on the shape of the gap, flat, round and pointed. At 50,000 volts per inch, a 0.001 inch gap would have 50 volts across it. The junctions in transistors and other solid state devices are much smaller and those 50 volts easily destroys the device. At NASA we determined what it would take to generate static charges on an astronaut's space suit in all conditions and what would be the effect on the "Fly by Wire controls". You don't want to be firing rocket thrusters at the wrong time or not at all.

Steve C, I can't explain why your car gets all charged up and without the charge being dissipated through the tires. Could be the tires don't have the conductive carbon. Maybe you have to stop wearing silk underwear.

Our police force has a few Mobil Command Vehicles, we have an 18 wheeler that we setup at events. The ground rods are built into the ends of the hydraulic leveling pads and if there is a fire hydrant near by we run a line to it. We also place dissipating mats at the steps in such a way that one cannot grab the hand rail without first standing on the mat.

At train stations, the train tracks and the station ground are bounded to protect passengers from being zapped getting on-off the trains.

 

[chapmx]

Agree Mike. Currently my tank has a single ground wire with clip. I believe I will add a second ground wire. Prior to fueling I will run ground wire 1 to truck frame (have a small bare spot on frame near rear wheel well) and wire 2 I will clamp to nozzle then start filling process. I agree with many here that the likelihood of an "incident" under normal circumstances is unlikely but these extra steps are very simple and really take little effort. In addition, I only need to fill these tanks about 3 times a year (set them up as I was tired of the the 5 gallon shuffle, in addition I am close to 10 miles from nearest fuel) so it hardly seems like much trouble to connect a couple clips a few times a year! I tend not to be overly safety conscious (must admit to many ER visits - mostly motorcycle related ) but due to an incident with a fuel can and a spark that a friend had in the past this topic was a little higher on my list of safety topics than most and I was curious as best methods to minimize the spark risk.

Thx again for the input. If you do not see any large explosions on the news things must be working!

 

[Steve C]

Steve C, I can't explain why your car gets all charged up and without the charge being dissipated through the tires. Could be the tires don't have the conductive carbon. Maybe you have to stop wearing silk underwear.

My truck only zap's me when the weather cools down and I am using the heater. I believe it is due to the lack of humidity in the air. I would have to find one of my old psycometric charts to be exact, but I think if you take 20 degree f. air that is at 70-80% relative humidity and run it through a heating coil that discharges it at 100+ degrees the relative humidity of that air drops down to 10-20%. Its conductivity is very low.

My little GMC Sanoma rides a little harsh and has cloth seats that contain a lot of synthetic fibers. The constant bouncing up and down with my back rubbing on the seat builds a pretty good static charge. I have experienced static discharge sparks of 1-1/4 to 1-1/2" in cold weather when closing the door of my truck.

At night it is pretty spetacular to look at but it can cause uncontroled outbursts of profanity and a lot of aerobic exercise jumping up and down and verbal discharges with the volume tied directly to the size of the spark

 

[Transit]

1-1/2 inch spark, that is 75,000 volts, you've just solved the energy shortage. Don't need no stinking wind mills; we have to get you wired to the power grid.

 

[Steve C]

1-1/2 inch spark, that is 75,000 volts, you've just solved the energy shortage. Don't need no stinking wind mills; we have to get you wired to the power grid.

yes it can make one blurt out loud sounds that aren't even words

They remind me of the time I was rebuilding the Edison-Spidorf magneto on my old Rototiller brand 2 cycle rototiller. The mag was as large or larger than you would expect to find on a full size tractor. The tiller had a huge spark plug that would fire even when it was totally oiled up. I think it ran a 20-1 mixture.

I didn't realize that there was a spring loaded cam in the mag to allow it to generate a spark at very low cranking speeds. I tried to twist the shaft to set the points and it felt like it was bound up.

I put a lot of extra force on it and I got it to move. When it did it snapped over center and gave me a jolt like I have never before experienced. I had a small garage at the time and I am sure I bounced off all 4 walls and possibly the loft before I could even utter a sound.

I put the mag back on the tiller and never touched it again....

 

[patrick_g]

For interest attached is a site for marine fuel tank installation.

I'm not positive but I believe you have to have a grounded tank by specifications and may not get fueled if you are not grounded.

http://www.moellermarine.com/sites/moellermarine/files/Fuel_Tank_Installation_Instructions.pdf

Egon, My wife and I did 10 years in the U.S. Coast Guard Auxiliary and among our duties other than ocean search and rescue and public education was vessel examinations where if the boat passes the owner gets a neat decal to put on it and if they fail they at least learn where they came up short so they can improve their situation.

Fuel tank/filler bonding/grounding was an important point. You'd be amazed at the condition of some of the boats both really good and really bad with expired rusty no pressure fire extinguishers, rotted straps on the PFD's (personal flotation devices AKA life preservers) and leaking fuel tanks.

One guy really won the prize. He was going to take a couple pre-teen kids out in the ocean fishing with PFD's that were so rotted they were falling apart, fire extinguishers with no pressure and the powder caked into a hard solid lump, and two portable fuel tanks for the outboard, both of which were leaking at the bottom seam. After he was given a list of his discrepancies (I didn't list them all here) he turns to me and asks, " does this mean I can't take the grand kids fishing?" My partner that morning was a retired police sergeant who immediently answered, "No, it means you SHOULDN"T."

Too bad his boat had no FEL bucket up front for the kids to ride in out through the choppy seas.

Pat

 

[Wis Bang]

I worked in the tank transport industry. During the 1990's we were required to install a Scully grounding point on our trailers. While we had grounding 'balls'; a spherical ball w/ a threaded tail inserted into a hole on the trailer frame, from the manufacturer. We were required to add new ones with an insulated section and a center point w/ a wire pigtail that was grounded w/ a fastener. This was due to a conversion of the solvent facilities to self loading. The loading rack computer would send a signal to the center point to verify the ground since there wasn't a loader present to verify that the unit was grounded.

The piping used to top load flamables is also grounded and is designed to be extended close to the bottom of the compartment so the 'splash' zone is reduced so the liquid rapidly bonds to the filler pipe.

Scary is standing on top of the trailer in a chemical storage/distribution facility and seeing blue sparks race around inside the trailer...

Every distribution hose has a ground wire that is exposed when the the connectors are inserted and banded to insure the hoses are bonded.

Emergency roadside transfer procedures include using jumper cables to bond the two trailers & the pump together and to a common ground for added protection.

 

[patrick_g]

I worked in the tank transport industry. During the 1990's we were required to install a Scully grounding point on our trailers. While we had grounding 'balls'; a spherical ball w/ a threaded tail inserted into a hole on the trailer frame, from the manufacturer. We were required to add new ones with an insulated section and a center point w/ a wire pigtail that was grounded w/ a fastener. This was due to a conversion of the solvent facilities to self loading. The loading rack computer would send a signal to the center point to verify the ground since there wasn't a loader present to verify that the unit was grounded.

The piping used to top load flamables is also grounded and is designed to be extended close to the bottom of the compartment so the 'splash' zone is reduced so the liquid rapidly bonds to the filler pipe.

Scary is standing on top of the trailer in a chemical storage/distribution facility and seeing blue sparks race around inside the trailer...

Every distribution hose has a ground wire that is exposed when the the connectors are inserted and banded to insure the hoses are bonded.

Emergency roadside transfer procedures include using jumper cables to bond the two trailers & the pump together and to a common ground for added protection.

Now there is some professional attitude and knowledge regarding safe grounding procedures!

I have seen videos from surveillance cameras at serve yourself filling stations showing fueling fires. Those fires were pretty scary stuff in and of themselves but the responses of some of the patrons would be really funny if it were not life threatening situations. Jump in and drive away with the nozzle still in your filler! Throw your hands in air and and run back and forth shouting oh my! For the most part the clearly marked emergency pump cut off switch, typically a large red panic button to press, is ignored.

One of the things a prudent person does as a part of maintaining their situational awareness above and beyond noting the actions of the other patrons at a gas stop is the location of the emergency pump shutoff. You never know when you might need to hit the panic button. Not to imply that you, gentle reader, would do anything to make it necessary but another patron might.

Pat

 

[two_bit_score]

The one thing I know is that after reading this thread from start to finish I'm afraid to put gas in my truck and my just have to get a horse.

 

[Steve C]

The one thing I know is that after reading this thread from start to finish I'm afraid to put gas in my truck and my just have to get a horse.

Isn't it great when you learn something even when you aren't trying!

I once built a dust collector for my wood shop. It used a plastic garbage can for a reciever and I built a cyclonic seperator mostly out of wood. I piped it with plastic pipe and powered it with a large shop vac moter and filter. I was very proud of the results, it extended my run times between shop vac filter changing about 10 times.

When it was running if you put your hand on the plastic tube it would make your hair stand on end. If you touched the cast iron top of the table saw at the same time it would make your eyes roll back in your head.

It was a dust explosion looking for a place to happen. I installed copper ground wires and bonded everything together anf the problem went away.

It gave me a great appreciation of what static electricity can do and where it comes from.

In my profession as a mechanical designer in chemical and nuclear power plants I always insured that everything was bonded and grounded but I actually didn't appreciate why until my dust collector project. If a little fractional horsepower motor in a shop vac can move enough material to build up a charge like that can you imagine what a 100 hp motor with miles of pipe or ductwork could do? Without bonds and grounds stuff would be blowing up every day!!!