In industries where control flow lines are used. The electric butterfly valve is widely used in the production line of metallurgy, steel-making, petroleum and so on. It can separate the pipeline system. The structure is characterized by the use of up and down lifting ram, allowing both sides of the valve to be pressurized.

To cut off or limit the flow of a pipe. The rare structures are single ram, double ram, parallel, wedge and so on. Butterfly valve is characterized by fast opening and closing speed, simple structure, low cost, but poor tightness and pressure capacity. The characteristics of the ball valve are similar to those of the gate valve, but it is difficult to achieve large caliber due to the limitation of volume and opening and closing resistance. The electric butterfly valve should be wafer type turbine driven hard seal butterfly valve, not flange type, and it does not have the function of eliminating water hammer. To solve the extrusion problem between the butterfly plate and the valve seat of the concentric electric butterfly valve, a single eccentric electric butterfly valve occurs. Its structural feature is the deviation of the valve stem axis The center of the butterfly plate is made, so that the upper and lower ends of the butterfly plate are no longer the rotation axis, scattered, and the excessive extrusion between the upper and lower ends of the butterfly plate and the valve seat is reduced.

In order to eliminate water hammer, it is necessary to add water hammer absorber or slow closing check valve. Only disc check valve with slow closing function can prevent water hammer. The sealing of ball valve usually uses flexible data, which is also difficult to use in high temperature and high pressure pipeline. In comparison, the sealing of electric butterfly valve is better than that of ball valve. The characteristic of check valve is to restrict the flow direction of medium and make the medium flow in one direction. Commonly used are swing type and lift type.