What are regulations for Pressure Relief System on ships ?

Pressure relief systems

Each cargo tank with a volume exceeding 20 m3 is to be fitted with at least two pressure relief valves of approximately equal capacity, suitably designed and constructed for the prescribed service. For cargo tanks with a volume not exceeding 20 m3, a single relief valve may be fitted.

If cargo holds with independent tanks may be completely closed, overpressure/vacuum relief valves are to be provided for in order to avoid pressure variations of more than 0,15 bar above and below atmospheric pressure.

Interbarrier spaces are to be provided with pressure relief devices complying with recognized standards.

The combined relieving capacity of the pressure relief devices for interbarrier spaces surrounding type A independent cargo tanks where the insulation is fitted to the cargo tanks may be determined by the following formula:



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