Which gas is NOT suitable for inerting a tank?

Carbon Dioxide is not suitable for inerting a tank primarily because its properties do not provide the inerting effect needed to prevent combustion or chemical reactions. Inerting requires a gas that can displace oxygen effectively and maintain a non-reactive atmosphere within the tank.

While nitrogen, hydrogen (in certain contexts), and helium are commonly used for this purpose due to their inert characteristics and ability to create a safe environment by reducing the oxygen concentration, carbon dioxide does not serve this function effectively. Instead, it can support certain combustion processes and can lead to the formation of corrosive environments if moisture is present, which can be detrimental in a tank environment.

Inert gases typically have low reactivity and do not contribute to combustion, making safe options like nitrogen, hydrogen in controlled applications, and helium more appropriate than carbon dioxide for inerting purposes.