Relief system for process fluids under pressure

摘要

A relief system for process fluids under pressure. The system includes a normally open isolation valve in fluid communication with a process system under pressure through an upstream conduit. A buckling pin actuator is in fluid communication with the upstream conduit through a sensing line. A spring activated actuator is engaged with the isolation relief valve in order to retain the isolation valve in a closed position. A buckling actuator bypass valve is supplied with non process fluid pressure to an input port and the buckling actuator bypass valve also includes a first output port to the spring activated actuator and a second output port to a vent whereby pressure in the process system above a predetermined level will actuate the buckling pin actuator, moving said buckling actuator bypass valve to said second outlet port to vent and thereby moving the spring activated actuator in order to open the isolation valve.