Static and plastic fuel cans/

[hihosland]

Is there any practical way to discharge any static build up when using plastic fuel cans, plastic funnels, plastic hoses and plastic fuel tanks?

 

And should we be worried anyway?

 

Is anyone aware of any incident serious or otherwise that was a result of a static discharge from plastic surfaces around aircraft?

 

Davidh

 

 

[Guest ozzie]

We have discussed this before.

 

Yes there are plenty of documented incidents of static induced fires caused by refuelling from and the filling of plastic containers. one of the most common is plastic containers being filled whilst sitting in the backs of utes that have a plastic protector lining. (rinocoating is one type). It is recommended to remove them and place them on the ground before refilling, make sure that the bowser nozzel contacts the container at all times. if you are really serious drill a hole in the container fit a bolt so that the fuel will contact it and fit a earth lead to the bolt and attach it to the fuel nozzel when filling and when fueling from the drum earth it to your aircraft.

 

The most dangerous conditions are when it is hot and there is a low humidity.

 

IE those hot dry westerly windy days are the most dangerous.

 

Use only APPROVED containers and funnels and HOSES (don't use a garden hose)ect.

 

I do belive that this topic should be covered fully and included in your training. it is merley treated as an afterthought.

 

When i was refuelling aircraft i used the Mobil refuelling handbook as a guide. And there are CASA rules to abide by as well.

 

Ozzie

 

 

[Yenn]

it is not only hot dry Westerlys that give static. The best display I have ever seen of static occured in very cold dry Westerly's.

 

 

[Guest ozzie]

Hot will give you a faster evaporation rate. more vapor higher chance of ignition. dry air ie low humidity enhances that risk. without digging into my books it is something about flash point from memory. Recommend studying the Dangerous goods course.

 

 

[ahlocks]

Get an alligator clip, a length of insulated copper wire and some light weight, small linked metal chain.

 

Attach the clip to one end of the wire and solder an end of chain to the other.

 

Place the free end of the chain into the plastic jerry can and then clip the alligator clip to the bonding point of the aircraft. The aircraft and the liquid are now at the same potential - no spark.

 

 

[facthunter]

Change chain.

 

Wouldn't a loop of solid copper/aluminium welding rod be preferable to a chain, as it is one piece? Nev

 

 

[ahlocks]

G'day Nev,

 

Gravity keeps the chain within the fluid as you pour from the jerry can. I.e. The chain will move to the lowest point of the container as you pour from it. You need to bunch enough chain onto the bottom of the container so that it 'pours' with the fluid.

 

Plus the chain coils up to a smaller parcel for storage.

 

Use a similar setup for bonding when doing HAZMAT recoveries.

 

Cheers!

 

Having to set up static bonding wasn't an issue at this one.There wasn't much left to recover...

 

[ATTACH]6802.vB[/ATTACH][ATTACH]6803.vB[/ATTACH]

 

 

 

 

[facthunter]

Ta.

 

Thought I would leave the wire in the container. If you think the connection between each link is not a problem Potentially.(pun intended) Nev..

 

 

[ahlocks]

Wire would work and is better that nothing.

 

The benefit of using the light chain is that is portable between containers and works without having to modify those containers, plus it 'pours' with the fluid and stays 'connected' to it to prevent the building up of a charge that could cause an arc.

 

Like all things liquid or gaseous and burny, there is a lower and upper explosive limit. The chance of a discharge between the links is possible but it is unlikely and even more unlikely that it will do any thing within the confines of the container owing to the upper explosive limit of the vapours or being immersed within the fluid (too rich).

 

I'll get some photos next time I'm fuelling the beer can.

 

 

[facthunter]

True.

 

You're right about the mixture being too rich in a full container. If you placed a flame near it it would only burn at the opening where the mixture would be in the ignitable range. I did have a static electric ignition event some years ago but it involved synthetic materials (cloth). Thanks for your response. Regards Nev.

 

 

[AlanB]

Grounding Query

 

Thanks for the info regarding plastic containers.

 

I have a question regarding grounding. Where do you ground a fibreglass aircraft?

 

My Sapphire has f/glass tanks in the wing with no dedicated grounding point.

 

Do I ground to the Mr Funnel I use when refuelling....supposedly the Mr Funnels coduct.

 

Or maybe to the metal drain valve at the bottom of the wing tank which would directly contact the fuel in the tank?

 

cheers Al

 

 

[Guest ozzie]

BTW if you are unsure if the plastic jerry can is of the approved type it should carry the Australian standards number on it. This correct number can be found at the bowser. there is a little warning sticker that says 'fill only metal and approved plastic containers, place on ground and nozzel to contact container' the approval number is underneath.

 

I belive that all aircraft are to have an earth point fitted near the filler clearly marked 'earth'. i assume that RAAus aircraft are not exempt from this reg.

 

The metal drain plug on the Sapphire would work as long as it has no fuel on it. I'd go for the exhaust stub if no earth point was available. It would earth back to the tank via the fuel in the line. A anti static mat that fits around the tanks fill point would be helpfull as well for all aircraft.

 

Ozzie

 

 

[hihosland]

Proposal for criticism.

 

take 1000mm light chain

 

At 750mm point gather up a 100mm loop and bolt that to the rim of the "Mr Funnel " funnel.

 

At end of short end fix an alligator clip.

 

In use

 

1...attach clip to earthed fuel tank

 

2...insert funnel into tank with short chain loop retained inside the funnel

 

3...drop long end of chain into Jerry can and proceed to pour.

 

When not in use the chain is stored inside the funnel.

 

Any dust etc collected by the chain will be caught by the funnel because the chain does not contact the fuel after it has been through the funnel's filter.

 

Comments???

 

Davidh

 

 

[trevorp]

number one,