Butterfly ValveChina DN50 2.5′′ FM UL Approved 300 Psi Grooved Butterfly Valve with Signal Gearbox Used in Fire Sprinkler System, Find details about China Wafer Butterfly Valve, Fire Fighting Valve from DN50 2.5′′ FM UL Approved 300 Psi Grooved Butterfly Valve with Signal Gearbox Used in Fire Sprinkler System