CO2 flooding system or central bank CO2 system is one of the common fixed fire fighting system installed on most of the ships. It releases carbon dioxide (CO2) in bulk quantity to a protected space (such as engine room, cargo hold, purifier room, pump room, etc.) under fire. Smothering action of CO2 extinguishes the fire thereby preventing spreading of fire to other parts of the ship. It consists of several CO2 cylinders located in a separate room, called CO2 room. These bottles contain CO2 in liquid state. When the fire in a protected space goes out of control or in a situation when the fire is not able to extinguish by local fire fighting media, CO2 flooding system comes into picture. CO2 from the bottles directed via common manifold, main valve and distribution pipe lines to nozzles through which it is released to the protected space for fire extinction. Due to safety reasons, the CO2 flooding system is manually released from a release cabinet located outside the protected space.

Low and high pressure CO2 is used for the fire protection of machinery spaces, pump rooms, cargo holds, paint stores and galley exhaust ventilation ducts on board ships.