MadSci Network: Engineering |
In fact, its more important to connect non-metal containers/nozzles than metal. This is because electrostatic charge ("static") builds up much more easily on insulators than it does on conductors - the electrons are unable to flow to/from earth.
When two unequally charged objects come close together, charge may jump across the gap in the form of the spark which would ignite the flammable liquid vapour. A plastic container could easily pick up charge through friction as it rubbed against things on the way to be filled, and this charge could them jump over to the metal nozzle, which, being a conductor, is likely to be earthed through the dispenser. It would behave as a lightning conductor does when a charged thunder cloud comes over.
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