How does an inert gas system on a tanker function to prevent explosions in cargo tanks?

Correct Answer: Option D — Inert gas dilutes the flammable vapor and air concentrations to keep them below the lower explosive limit.

Inert gas systems, required by 46 CFR 32.53, replace oxygen-rich air with gas containing less than 8% oxygen. By maintaining the atmosphere below the concentration required for combustion, the system prevents the formation of a flammable mixture, effectively eliminating the risk of explosion within the cargo tanks during operations.