Openings in cargo tanks are to be so located and arranged that no ignitable gas mixtures can be formed in closed spaces containing sources of ignition or in the vicinity of sources of ignition on deck.
The venting of cargo tanks may be effectedonly through approved pressure/vacuum relief devices which fulfil the following functions:
Passage of large air or gas volumes during cargo loading/unloading and ballast operations, and
The flow of small volumes of air or gas during the voyage.
Venting arrangements may be fitted individually on each tank or may be connected to a common header system or to the inert gas system.
