Grounding Strap for a Gas Tank?

[Kevin_H.]

Does any one know if we need a grounding strap for a fuel tank on the back of the flat bed? We want to be able to fill the tank in town and then remove it once we get home. The tank will need to be on 4x4 runners so that we can get the forks under it.



The tank is 100 gal square dot approved.

[DanG]

I don't think grounding the tank to the truck is going to help unless the truck is grounded. If it is your own safety you are concerned about, you could just touch the nozzle to the tank, to discharge any static, before opening the tank.  I complying with a law is your concern, do whatever they reccommend, which probably has no basis in practicality. :  You can still do the nozzle touch thing for safety. ;) :D

Most aircraft use a wire that is attached to the nozzle and plugs in to a grounding recepticle on the aircraft. 

Don't forget to ground yourself before touching the tank around the filler neck. That would be the most likely time to touch something off, especially when you've been pumping fuel in, stirring up lots of fumes.  Your body can generate a static charge of up to 15,000 volts, and throw quite a little lightning bolt.  In the phone biz, we used to wear a grounding strap around our wrist, and plug it into a grounded jack before handling any static-sensitive equipment. 

One trick to avoid the jolt you sometimes get when opening your car door, is to touch a metal object to the car first.  I use my watch. The spark is between the watch and the car, so I don't feel it. It's a wonder I haven't blown the DanG thing up. :D :D

Kevin, I know that you are aware of this stuff, but there may be some folks reading here that don't. ;)

[Kirk_Allen]

Not sure of the grounding requirements but even though its a DOT approved tank you may find that you need the proper plaquerd label while hauling fuel.  I dont know what the law is on quanitiy but if your transporting any Hazordous Material there are some nasty fines that can be issued if not labeled properly.  I know around where we live I could get away with it all day and no one would think a thing of it but not sure what type of enforcement issues you may have in your area.

[Kevin_H.]

Thanks for the input guys, some very sound advise, We are going to do our best to stay with in the law. :D

We have a diesel tank that gets filled up with one phone call, but they dont deliever gas, seems they cant compete with the local walmart gas price so they dont even carry it. :(

[sigidi]

Kevin,

I know this is the other side of the world, but here in Aus if you are carrying bulk fuel defined as more than 100litres (sorry not up on conversions for the fluid) then you need to carry a shippers declaration for transport of dangerous goods surface mode and also the releveant dangeous goods signs including but not limited to front and back classification signs and emergency data signs on both sides, you also need to carry MSDS Material safety Data Sheets fo rwhatever you are carrying plus apropriate fire extingushers if flammable commodity.

[Sawyerfortyish]

Wow Walmart sells gas ??? ?. Hmmm I guess i'm not surprized. I have 2 fuel tanks that I do just like you want to do Kevin. But I only fill them with diesel. In my state you can transport up to 100 gal in a dot approved tank with no problems. If it were me getting gas I think I would take a log chain or cable and drap it over the tank and against the truck frame. Just my two cents.
  Oh yea make sure you have a fire extingusher and paid up life insurance   ;);D ;D :D

[DanG]

Yep, SF-ish, Wally World has gas.  They are usually the cheapest place in our town, by a penny or so.  You can get a 3 cent discount at the pump by buying a prepaid card in the store.  In our case, WM is usually undersold by 5 or 6 cents by the Flyin'J and Pilot truck stops at the next exit.

Wrapping the chain around the tank ain't gonna help.  The key is to complete an electrical circuit from the pump's nozzle to the tank.  For maximum protection from static spark induced explosion, a very rare occurrance,  ground the tank to the truck. Then use a small wire with clips on the ends to connect the truck to the pump's nozzle.  Connect it to the nozzle first, then to a point on the truck, well away from the tank's opening.  The reason that grounding to the truck doesn't help, is that the truck is insulated from the ground by the tires.  The reason for connecting to the nozzle first, is that the spark will happen at the LAST connection point, and you don't want that to be near the fuel.  Once the tank and nozzle are electrically connected, no difference in electrical potential exists, thereby no spark can be generated.

[Kirk_Allen]

Dang makes a very valid point on the grounding issue.  While refueling Aircraft you always plug into the Aircraft first and then the grounding point.  Especially during Hot refuels (Engines Running).  I was amazed to see how much static charge is built up on an aircraft that just landed. 

[DanG]

There have been people electrocuted by the static discharge from hovering helicopters coming into contact with them while they were grounded to the Earth.  The static charge is built up from the friction of the aircraft and it's parts moving through the air.  The hazard is lessened when the air is moist, as the moisture conducts some of the charge away from the aircraft.  Motor vehicles have the same problem, only to a lesser degree.  The problem in motor vehicles would be entirely eliminated if there were tiny metallic fibers in the rubber of the tires.  People who work with static sensitive electronic stuff sometimes wear shoes with such fibers in the soles.

[Kevin_H.]

it seems like I can remember seeing a grounding strap on a truck before, It hung down from an axle or the frame and would make contact with the ground when the truck was stopped. It might have even been on one of the fire trucks?

I looked all over the web today to try and find out how much fuel I could carry, but the illinois state web sites are just next to being usless >:(
I think it is 100 gal, since that is what all the farmers seem to have in the back of there trucks, well thats what I'm going with anyway.

[sawguy21]

I worked in the helicopter industry for a number of years. I set up a lot of refuelling systems and static grounding was very important. The points made here are critical to safe handling of fuel.
I never heard of anyone getting killed by the static in a longline but some pilots thought it was worth a hoot to make the ground guy grab a swinging hook. The shock would park him on his butt. Some ground crew carried a short grapple hook that was grounded with a/c cable to a tent peg.

[rebocardo]

> it seems like I can remember seeing a grounding strap on a truck before

Natural gas company trucks, they look like film strips that flip up while driving and when stopped they touch the ground. They use to come on older "luxury" cars too.

I would ground the tank to the frame with a 4 gauge cable and 1/4 bolts with serrated washers. If you are doing this more then once a week, then I would use a welders clamp on one end and clamp at the bottom of the tank (vapors rise).

I think the real hazard is during the off load process. First, many cheaper tanks are not meant to take the stress of being moved while full (100 gallons of gas x 6.3 pound = 650 pounds of gas) and might distort while being moved. I would make sure I did not disconnect ground until the tank was grounded to the forklift.

If this me, I would look into making a small trailer or using a used 4x8 utility trailer, securing and armoring the tank in case someone hit the trailer, and just parking it where I needed it after filling it up. Constantly filling and then moving a tank full of gas seems like an accident waiting to happen after you have done it 100 times. I think this is a cleaner solution.

[DanG]

A 4 guage cable wouldn't be necessary.  Static grounding is a high voltage, low current situation.  A small braided strap would be sufficient, but the quality of the connection is important.  Static discharge is comparable to the spark plug on a gas engine. A tiny wire and a good connection will get the job done.

Static straps hanging down from a vehicle might help, but I wouldn't rely on them. They have to be in contact with a good earth ground to be effective.