Compared with conventional gate and globe valves, butterfly valves achieve high performance near to perfection with its pressure resistance and durability. Especially in vessels, the Butterfly Valves enjoy high reliability and when compared with the conventional valves, the Butterfly Valves are excellent in the following aspects: (1) light and compact, (2) maintenance is easy, (3) labour-saving ease of operation, and (4) low cost. 1. Lock Lever Actuator: Generally used in small diameters. Opening and closing operations can be done with a light one-touch device, by turning the lever to only 90 degrees. Moreover, flow regulation is available with a ten-step locking device. Opening degrees are indicated by the tip of the lever.