5.6 Cargo transfer arrangements
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Statutory Documents - IMO Publications and Documents - Resolutions - Maritime Safety Committee - Resolution MSC.370(93) – Amendments to The International Code for The Construction and Equipment of Ships Carrying Liquefied Gases In Bulk (IGC Code) – (Adopted on 22 May 2014) - Annex - Amendments to The International Code for The Construction and Equipment of Ships Carrying Liquefied Gases In Bulk (IGC Code) - Chapter 5 — Process Pressure Vessels and Liquid, Vapour and Pressure Piping Systems - 5.6 Cargo transfer arrangements

5.6 Cargo transfer arrangements

  5.6.1 Where cargo transfer is by means of cargo pumps that are not accessible for repair with the tanks in service, at least two separate means shall be provided to transfer cargo from each cargo tank, and the design shall be such that failure of one cargo pump or means of transfer will not prevent the cargo transfer by another pump or pumps, or other cargo transfer means.

  5.6.2 The procedure for transfer of cargo by gas pressurization shall preclude lifting of the relief valves during such transfer. Gas pressurization may be accepted as a means of transfer of cargo for those tanks where the design factor of safety is not reduced under the conditions prevailing during the cargo transfer operation. If the cargo tank relief valves or set pressure are changed for this purpose, as it is permitted in accordance with 8.2.7 and 8.2.8, the new set pressure shall not exceed Ph as is defined in 4.13.2.

  5.6.3 Vapour return connections

 Connections for vapour return to the shore installations shall be provided.

  5.6.4 Cargo tank vent piping systems

 The pressure relief system shall be connected to a vent piping system designed to minimize the possibility of cargo vapour accumulating on the decks, or entering accommodation spaces, service spaces, control stations and machinery spaces, or other spaces where it may create a dangerous condition.

  5.6.5 Cargo sampling connections

  5.6.5.1 Connections to cargo piping systems for taking cargo liquid samples shall be clearly marked and shall be designed to minimize the release of cargo vapours. For vessels permitted to carry toxic products, the sampling system shall be of a closed loop design to ensure that cargo liquid and vapour are not vented to atmosphere.

  5.6.5.2 Liquid sampling systems shall be provided with two valves on the sample inlet. One of these valves shall be of the multi-turn type to avoid accidental opening, and shall be spaced far enough apart to ensure that they can isolate the line if there is blockage, by ice or hydrates for example.

  5.6.5.3 On closed loop systems, the valves on the return pipe shall also comply with 5.6.5.2.

  5.6.5.4 The connection to the sample container shall comply with recognized standards and be supported so as to be able to support the weight of a sample container. Threaded connections shall be tack-welded, or otherwise locked, to prevent them being unscrewed during the normal connection and disconnection of sample containers. The sample connection shall be fitted with a closure plug or flange to prevent any leakage when the connection is not in use.

  5.6.5.5 Sample connections used only for vapour samples may be fitted with a single valve in accordance with 5.5, 5.8 and 5.13, and shall also be fitted with a closure plug or flange.

  5.6.5.6 Sampling operations shall be undertaken as prescribed in 18.9.

  5.6.6 Cargo filters

 The cargo liquid and vapour systems shall be capable of being fitted with filters to protect against damage by extraneous objects. Such filters may be permanent or temporary, and the standards of filtration shall be appropriate to the risk of debris, etc., entering the cargo system. Means shall be provided to indicate that filters are becoming blocked, and to isolate, depressurize and clean the filters safely.

Parent topic: Chapter 5 — Process Pressure Vessels and Liquid, Vapour and Pressure Piping Systems
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