What is the advantage of pilot-operated relief valves over the spring loaded?
The IMO Gas Codes require that all liquefied gas carrier cargo tanks are fitted with pressure relief valves. Pilot-operated relief valves are frequently used, particularly with refrigerated cargoes. The main advantage of using pilot operated relief valves rather than simple spring loaded types for refrigerated liquefied gas cargoes tanks is that they ensure accurate operation at the very low cargo carriage pressures.
