Why does an oil tanker connect a metal wire to the ground when transferring fuel?

Why does an oil tanker connect a metal wire to the ground when transferring fuel?

• A. To transfer static charge that builds up to the ground, to prevent ignition of fuel
• B. To measure hull integrity
• C. To drain fuel
• D. To ground negative battery

Answer: (A)

Static electricity can build up when fuel moves through pumps and hoses, especially with hydrocarbons that pick up charge as they flow and contact surfaces. If that charge isn’t removed, a spark could form when the charged metal surfaces come into contact with a ground, another conductor, or when vapors are near a potential difference, and that spark could ignite the flammable vapors in the air. Connecting a metal wire from the tanker to the ground provides a direct path for the static charge to flow into the earth, equalizing the electrical potential of the tanker, pipelines, and dock equipment. This bonding prevents a discharge spark from occurring during fueling, greatly reducing the risk of ignition. So, the purpose is safety: to dissipate static buildup and keep ignition sources away from flammable vapors. It's not about measuring hull integrity, draining fuel, or grounding a battery.

Static electricity can build up when fuel moves through pumps and hoses, especially with hydrocarbons that pick up charge as they flow and contact surfaces. If that charge isn’t removed, a spark could form when the charged metal surfaces come into contact with a ground, another conductor, or when vapors are near a potential difference, and that spark could ignite the flammable vapors in the air.

Connecting a metal wire from the tanker to the ground provides a direct path for the static charge to flow into the earth, equalizing the electrical potential of the tanker, pipelines, and dock equipment. This bonding prevents a discharge spark from occurring during fueling, greatly reducing the risk of ignition.

So, the purpose is safety: to dissipate static buildup and keep ignition sources away from flammable vapors. It's not about measuring hull integrity, draining fuel, or grounding a battery.