The Maritime Safety Committee, at its 107th session (31 May to 9 June 2023), with a view to providing more specific guidance for the application of the relevant requirements of the International Code of Safety for Ships Using Gases or Other Low-flashpoint Fuels (IGF Code), approved unified interpretations of the IGF Code, prepared by the Sub-Committee on Carriage of Cargoes and Containers, at its eighth session, as set out in the annex.
Member States are invited to use the annexed unified interpretation as guidance when applying the relevant provisions of the IGF Code and to bring them to the attention of all parties concerned.
PART A-1 SPECIFIC REQUIREMENTS FOR SHIPS USING NATURAL GAS AS FUEL
Chapter 9 Fuel supply to consumers
9.2 Functional requirements
Paragraph 9.2.2 states:
"the piping system for fuel transfer to the consumers shall be designed in a way that a failure of one barrier cannot lead to a leak from the piping system into the surrounding area causing danger to the persons on board, the environment, or the ship"
To comply with part A-1, paragraphs 9.2.2, 9.6.1 and 126.96.36.199 of the IGF Code, two independent safety barriers should be in place, while, as far as practicable, using a minimum of flange connections.
There should be, no single common flange or other component where one single failure itself may overcome both primary and secondary barriers and may result in a gas leak into the surrounding area causing danger to the persons on board, the environment, or the ship.
A single common flange (with two sealing systems) may be accepted at the fuel connection to the gas consumers including GCUs, boilers, and components on the engine, such as gas regulating units.