APPARATUS FOR PERMITTING UNINTERRUPTED RELIEF OF CARGO TANK COMPARTMENT INTERNAL PRESSURE AND PREVENTING LEAKAGE OF LADING FROM THE CARGO TANK DURING DYNAMIC PRESSURE SURGES

摘要

The invention disclosed relates to an apparatus for permitting uninterrupted relief of cargo tank compartment internal pressures while also preventing the leakage of lading from the cargo tank to the surrounding atmosphere during sudden increases in the cargo tank internal pressure. According to one embodiment of the present invention, the cargo tank compartment pressure relief valve comprises a flow chamber coupled to an opening in the cargo tank compartment wall, wherein the flow chamber has a first opening in flow communication with the tank compartment and a second opening in flow communication with the atmosphere, whereby the first opening is under the control of a downwardly biased first vent head and the second opening is under the control of a downwardly biased second vent head.