What is the purpose of a bonding strap around tanks or vessels?

• A. To connect to a remote signal.
• B. To insulate the tank from the ground.
• C. To ensure equipotential across metal structures to prevent shock and reduce corrosion at differing potentials.
• D. To create an electromagnetic field to deter corrosion.

Answer: (C)

Equipotential bonding between metal tanks and other nearby metal structures is used to keep all those conductive parts at the same electrical potential. A bonding strap provides a low-impedance path between the tank and other metal components (like piping, supports, or a metal enclosure) so they share one common potential. This reduces the risk of electric shock if someone touches the tank while standing on grounded equipment and, at the same time, helps prevent corrosion that can occur when different metals sit at different potentials in an electrolytic environment.

It’s not for signaling or insulation, and it doesn’t work by creating an EM field to deter corrosion—the purpose is to equalize potential and provide a safer, more corrosion-resistant electrical system.