Approved to Factory Mutual (FM) Class 7400, 7420 and 7422, the AT shut-off valves and valve assemblies feature a spring-return automated ball valve, explosion-proof limit switch and solenoid pilot valve, advanced quarter-turn rack-and-pinion actuator design, superior valve seating, and a patented stem-seal system. The valves are available in three-piece models or flanged models, with Type 316 stainless steel or WCB carbon steel trim, in sizes from 1/4 in. to 6 in.