Why do petrol tankers earth their fuel pipes?
hi The fuel lines are earthed in order to remove/reduce the possibility of sparks/arcing etc that could be generated by static electricity or some other source (maybe a faulty connection etc). If a voltage were to build up on an un-grounded pipe, this could easily cause a spark when, for example, the pipe was dragged across the ground/body of a vehicle or aircraft. Obviosly not a good idea! In an earthed system any voltages generated would be shorted down to ground (usually but not necessarilly 0v), which would make it impossible for any charge to build up, removing the threat of sparking.
