5.1 Inerting of tanks
Clasification Society 2024 - Version 9.40
Statutory Documents - IMO Publications and Documents - Specifications and Manuals - Inert Gas Systems - 5 Application to Cargo Tank Operation - 5.1 Inerting of tanks

5.1 Inerting of tanks

  5.1.1 Tanks that have been cleaned and gas-freed should be re-inerted preferably during the ballast voyage to allow the inert gas system to be fully tested prior to cargo handling. Purge pipes/vents should be opened to atmosphere. When the oxygen concentration of the atmosphere in the tank has fallen below 8% the purge pipes/vents should be closed and the tank pressurized with inert gas.

  5.1.2 During the re-inerting of a tank following a breakdown and repair of the inert gas system, non-gas-free and non-inerted tanks should be re-inerted in accordance with 5.1.1. During inerting, no ullaging, dipping, sampling or other equipment should be inserted unless it has been established that the tank is inert. This should be done by monitoring the efflux gas from the tank being inerted until the oxygen content is less than 8% by volume and for such a period of time as determined by previous test records when inerting gas-free tanks to ensure that the efflux gas is fully representative of the atmosphere within the tank.

  5.1.3 When all tanks have been inerted, they should be kept common with the inert gas main and maintained at a positive pressure in excess of 100 mm water gauge during the rest of the cycle of operation.

Copyright 2022 Clasifications Register Group Limited, International Maritime Organization, International Labour Organization or Maritime and Coastguard Agency. All rights reserved. Clasifications Register Group Limited, its affiliates and subsidiaries and their respective officers, employees or agents are, individually and collectively, referred to in this clause as 'Clasifications Register'. Clasifications Register assumes no responsibility and shall not be liable to any person for any loss, damage or expense caused by reliance on the information or advice in this document or howsoever provided, unless that person has signed a contract with the relevant Clasifications Register entity for the provision of this information or advice and in that case any responsibility or liability is exclusively on the terms and conditions set out in that contract.