Within petroleum marketing operations, bond has to do with electricity. A bond is an electrical conductor placed between two metal structures–between an aircraft refueler and an airplane, for instance–to prevent the build-up of static electricity.
If you watch a fueling procedure at an airport, you will notice that the refueling operator, before he attaches the fueling nozzle into the wing of the aircraft, will unreel a small-diameter cable from the back of his vehicle. He then clips the end of this cable to the airplane itself. This connection between the truck and the plane serves as a bond, and prevents the accumulation of static electricity, often generated by the flow of fuel, at a high velocity, through the pump, hose, and nozzle. The bonding connection serves to prevent the build-up of electrical charges between the bonded components.
See also Grounding.