Inertizated means that the vessel interior has been filled with an "intert" gas such as dry nitrogen.
Of course, nitrogen is not a chemically inert gas and hence the production of NOx in combustion processes.
The word "inert" in this case means that combustion is not possible in a pure nitrogen atmosphere, and that as oxygen and moisture are absent, since the nitrogen is pure and dry, the rusting of the vessel surface is prevented.
Am I right, José?
Giovanni S. Crisi
Sao Paulo - Brazil