What safety measure is sometimes used to minimize static electricity while filling above ground flammable storage tanks?

The correct choice focuses on the implementation of safety measures to mitigate static electricity, which is a significant concern when dealing with flammable materials, such as those in above ground storage tanks. In this context, grounding cables serve to dissipate static electricity by providing a direct path for electrical charge to flow into the ground, thereby reducing the risk of ignition from static discharge.

Static electricity can accumulate during the filling process due to the movement of liquid within the tank, creating friction and generating charges on the tank and its contents. Grounding cables help ensure that both the tank and the filling equipment are at the same electrical potential, effectively preventing the build-up of static charge.

Electron flow detection systems, while innovative, primarily monitor electrical currents rather than directly preventing static electricity build-up. Pressure relief valves and flame arresters serve critical roles in preventing overpressure and mitigating flame propagation, respectively, but are not effective in addressing static electricity concerns directly.

In conclusion, utilizing grounding cables is vital in minimizing the risk of incidents related to static electricity during the filling of flammable storage tanks due to their role in safely dissipating electrical charges.