Which of the following does not depict the tank inerting process on a tank vessel?

The tank inerting process is primarily aimed at creating a safer environment by reducing the oxygen content within the tank to levels that minimize the risk of combustion. In this context, the introduction of inert gas or nitrogen gas serves to displace oxygen, thereby preventing potential explosive atmospheres.

The option that describes the introduction of oxygen into a gas-free tank prior to entry does not align with the purpose of tank inerting. Inerting is fundamentally about reducing oxygen levels; therefore, adding oxygen contradicts this principle and could potentially create a hazardous situation.

Inert gas is added to a cargo tank during the discharge process or in advance of cargo loading to maintain a controlled atmosphere, preventing flammable vapors from accumulating. Similarly, the use of nitrogen gas also serves the same purpose in inerting tanks by lowering oxygen concentration. Each of these processes helps ensure that the atmosphere within the tank remains inert and safe, which is essential for safe operations on tank vessels.