the actuated butterfly valves are suitable for heating and cooling applications. they can also be employed for industrial applications, general services and water treatment. the vb series is equipped with standard on/off or modulating (4~20ma,) control quarter-turn electric actuator. features 1. cast iron or nodular cast iron wafer body 2. centric butterfly valve with elastomer liner 3. for on/off or modulating control 4. manual override non-clutch design. manual operation can be operated without any lever, clutch or brake upon power voltage. 5. visual mechanical position indicator for accurate visual reference of valve position 6. anti-condensation heater and 2 aux. limit switches on standard model 7. worm gear permanently lubricated and self locking 8. stall protection built-in thermal protection valve flow media cold and hot water, water with max. 50% volume of glycol temperature of medium -10°c.. +100°c rated pressure 1600 / 2760kpa leakage rate air bubble-tight (bo 1, din 3230) size dn150-dn500 material body cast iron or nodular cast iron ,shaft stainless steel, disc ductile iron with epoxy coating liner epdm actuator actuator qcf/qcm output torque 200-2500n.m power supply ac220v or ac/dc24v run time 15s~,90s operating power 40~200va output angle 90°± 3° on/off control signal 1 wire or 2 wire control modulating control signal 4~20ma feedback signal 4~20ma installation position upright to horizontal（no upset） protection class ip66 ambient conditions - 10°c .to 55°c 0..90% rh weight 1.5~50kg material steel. aluminium alloy