8900 SERIES MANWAY EMERGENCY RELIEF VENTS FLAT FACE FLANGE - BOLTING PATTERN TO ASME 150# SPECIFICATION; 24" SIZE; SPECIAL BASE MATERIAL / CONSTRUCTION; FLUOROCARBON ELASTOMER (FKM) DIAPHRAGM; MODEL 8910 TOP GUIDED - SPRING LOADED DESIGN FOR PRESSURE ONLY RELIEF; > 4 - 6 PSIG PRESSURE SPRING RANGE; PER SPQ NUMBER 57176 SPECIAL; 304SST BASE WITH ALUMINUM TOPWORKS CONSTRUCTION