Lug Butterfly Valves is a type of valve with a simple design and is generally only used for low-pressure flow. The design is very simple, so that in controlling the flow, to fully open and fully close only needed fourth round.
Valves can be operated manually, either by using a handle, lever pedal and so on. In addition to manually operated, there is also the type of valve automatically operated, ie control is done using the principle of change of flow, pressure and temperature in the pipes. The third change will affect the diaphragm, spring or piston so that it will automatically move the valve to open and close system.