Ventilation and gas-freeing

Ventilation and gas-freeing

• Outlet openings for gas-freeing cargo tanks are to be located as far as possible from air/inert gas inlet openings at a height of at least 2 m above the deck.
• The gas/air mixtures are to be discharged vertically.
• Outlet openings for gas-freeing of cargo tanks shall be so designed that, taking into account the capacity of the fan, the exit velocity of the gas/air is at least 20 m/s.
• On ships with inert gas systems, the free area of the vent openings shall be so designed that an exit velocity of at least 20 m/s is maintained if 3 cargo tanks are simultaneously purged with inert gas.
• The openings for gas-freeing are to be fitted with screw-down covers.
• On ships without inerting systems, the vent openings used for gas-freeing are to be fitted with flame arresters.
• The fitting of flame arresters may be dispensed with if a velocity of at least 30 m/s in the vent openings is proven.