Road Tanker Tyres Conducting/Non Conducting ?

[unbiased]

Are the tyres of motor vehicles conductive or non conductive for electricity? Is yes then why are the tankers earthed while loading? I think I know the answer but am not sure.

 

[sdifox]

non conductive. That is why the trucks have a earthing chain on them. Static buildup is bad for fuel truck and surrounding objects

 

[patentman]

Last I checked virtually all rubber, unless it contains some conductive agent, i.e. metallic particles, is non-conductive.

 

[Bassyhead]

Older rubber compounds used in tires were slightly conductive. Newer tires use a different compound that has less rolling resistance, but it's also virtually non-conductive which is why you see those chains and you get more static shocks in the winter when getting out of a vehicle.

 

[dkozloski]

Aircraft refueling trucks, which is one area of my expertise, have ordinary rubber truck tires that are in my case the best buy available. They need not drag chains as a grounding feature. Before refueling of an aircraft starts, a grounding cable is connected between the truck and the aircraft. If a hydrant refueling system is in the loop it is also connected to the other two units. The military also requires a connection to an earth ground if one is available. The big source of static electricity in refueling is the flow of fuel through the hoses which can act like a giant Van de Graff generator. When flow hits 250GPM, depending on the size of the hose which determines flow velocity, you can get almost a continuous arc if the system is not properly bonded together.

 

[Bassyhead]

Originally posted by: dkozloski
Aircraft refueling trucks, which is one area of my expertise, have ordinary rubber truck tires that are in my case the best buy available. They need not drag chains as a grounding feature. Before refueling of an aircraft starts, a grounding cable is connected between the truck and the aircraft. If a hydrant refueling system is in the loop it is also connected to the other two units. The military also requires a connection to an earth ground if one is available. The big source of static electricity in refueling is the flow of fuel through the hoses which can act like a giant Van de Graff generator. When flow hits 250GPM, depending on the size of the hose which determines flow velocity, you can get almost a continuous arc if the system is not properly bonded together.

Wow, I didn't realize fuel flowing through a hose could create such a large charge.

 

[herm0016]

most of the hoses also have a wire in them for fuel trucks, so the truck is grounded to the tank wich is in the ground.

 

[MetalStorm]

When aircraft land the first thing that is done is they are connected to earth - they can build up a HUGE charge flying through the atmosphere at speed and if you were to touch it without being earthed you could be in serious trouble!

 

[dkozloski]

MetalStorm. This applies mainly to hovering helicopters and it's more like everyone likes to see the newbie get zapped when he grabs the hook. Aircraft are equipped with static discharge wicks to dissipate the charge in the interest of efficient communications.

 

[MetalStorm]

Dkozloski would you be able to explain to me how they work, I'm not great when it comes to electricity! Are you saying that the aircraft can disipate the charge build up while it's flying? Or only when it lands, I thought the concept of earthing something is obviously when it's attached to earth so how would earthing in mid flight work? I'm quite interested to know more. Cheers.

 

[dkozloski]

Static charges are attracted to sharp points. Static discharge wicks look like small paint brushes with frazzled, conductive, bristles attached to the trailing edges of control surfaces. These dissipate the static charge as it accummulates. The static charge collects most quickly while the aircraft is flying through precipitation and adversely affects radio communicaton.

 

[DrPizza]

Originally posted by: MetalStorm
Dkozloski would you be able to explain to me how they work, I'm not great when it comes to electricity! Are you saying that the aircraft can disipate the charge build up while it's flying? Or only when it lands, I thought the concept of earthing something is obviously when it's attached to earth so how would earthing in mid flight work? I'm quite interested to know more. Cheers.

dkozloski answered your question... if you'd like to see this in action, and have access to a van de graff generator, hang onto the van de graff and hold a paper clip pointed outward... then , unfold the paperclip and point a pointy end outward.. Big difference in what you'll observe. Or, if you have someone else do this, hold your hand near the paper clip. In the latter case, it should be quite obvious that it's discharging much more of the static buildup than in the former case.

 

[Calin]

Originally posted by: dkozloski
Aircraft refueling trucks, which is one area of my expertise, have ordinary rubber truck tires that are in my case the best buy available. They need not drag chains as a grounding feature. Before refueling of an aircraft starts, a grounding cable is connected between the truck and the aircraft. If a hydrant refueling system is in the loop it is also connected to the other two units. The military also requires a connection to an earth ground if one is available. The big source of static electricity in refueling is the flow of fuel through the hoses which can act like a giant Van de Graff generator. When flow hits 250GPM, depending on the size of the hose which determines flow velocity, you can get almost a continuous arc if the system is not properly bonded together.

Van der Graaf I think.
But yes, the fuel don't conduct electricity and the rubber hose won't either - and the friction between the two can create a charge. A static charge can increase the voltage to values high enough to create sparks

 

[DrPizza]

Hmmm, I wonder if there is one correct spelling and LOTS of places where it is spelled incorrectly, or if there are more than one acceptable way to spell it.

 

[dkozloski]

So far I've found: Van De Graff
Van de Graaf
Van der Graaf
Van der Graff
Van der Graaff

Are there any more?