Emergency Contact The Importance of Maintaining Air Pipes and Associated Closing Devices on the Deck Home Latest updates Publications The Importance of Maintaining Air Pipes and Associated Closing Devices on the Deck 23 Apr 2024 Download page as PDF Sign up for alerts Air pipes are a common feature on the freeboard or superstructure decks of a vessel and ensure that the air pressure inside the associated ballast tank, or other compartment, remains the same as atmospheric pressure. Thereby allowing air to flow to prevent pressure build-up or vacuum formation. However, enabling this air flow introduces the requirement to ensure that weathertight integrity of a vessel is maintained during sea voyages by providing a means of closing. The closing device on an air pipe is an essential safety feature and therefore must be maintained to ensure that the vessel meets the applicable statutory standards. Defective closing devices or air pipes may allow water to ingress into the tanks during heavy seas, affecting stability and leading to listing or, in worst cases, foundering of the vessel. Regulations One of the main objectives of The International Load Lines Convention is the weathertight and watertight integrity of the vessels. Annex I, Regulation 20 1 of the convention sets out the requirements related to air pipes. Some of the pertinent points are summarised below: The height of air vent pipes from the deck to the point where water may have access below shall be at least 760 mm on the freeboard deck and 450 mm on the superstructure deck. Where these heights may interfere with the working of the ship, a lower height may be approved, provided that the Administration is satisfied that the closing arrangements and other circumstances justify a lower height. For vessels constructed after 01/01/2005 (registered with a Flag State, which is a party to the Load Lines Convention 1988 protocol), air pipes shall be provided with automatic closing devices.  For other existing vesse