SAFETY RELIEF VALVE FOR PRESSURE VESSELS

摘要

A fluid pressure safety relief system for a pressure vessel (10) having a main valve member (46) seating on a nozzle ring (38) under a mechanical force of a predetermined amount resulting from a calibrated counterweight (54). An operating rod (55) is connected between the main valve member (46) and a piston (74) having one side in fluid communication with fluid pressure in the pressure vessel (10). A fluid chamber (78) is provided on the other side of piston (74) and a fluid passage (84) from fluid chamber (78) has an outlet at its upper end (86) closely adjacent the nozzle ring (38). Upon unseating of the valve member (46) from the nozzle (38) fluid flows from the fluid chamber (78) to increase the fluid pressure differential across the piston (74) to assist in the movement of the main valve member (46) to an open position.