Electric double eccentric butterfly valve how to choose and installation direction

Electric double eccentric butterfly valve cut off and throttling effect in the pipeline, electric double eccentric butterfly valve opening and closing pieces is a disc-shaped disc, rotating around its own axis in the valve body, so as to achieve opening and closing or regulating the flow through the pipe cross-section The purpose of the size. The traditional butterfly valve can only be used at room temperature, low pressure and tightness less demanding occasions. With the continuous development of new process technology and material industry, butterfly valves can replace most of the traditional valves and are widely used in all fields of industry. According to the structural characteristics of the butterfly valve, it can be divided into center, single eccentric, double eccentric and triple eccentric. Among them, the newly developed triple eccentric butterfly valve is being promoted and used by advanced industrial countries in Europe and America with its unique advantages.

On the basis of single eccentric butterfly valve to further improve the forming is the most widely used double eccentric butterfly valve, the structural features of the stem axis deviation from the center of the disc but also the center of the body. The second eccentric shaft that will be divided into more than one side of the disc less two parts, this eccentric butterfly valve can be opened and closed in the process of quickly from the valve seat, a substantial elimination of unnecessary disc and valve seat The squeeze, scratch phenomenon, reducing the open resistance, wear and reduce the seat life increase. Scratch significantly reduced, but also makes double eccentric butterfly valve can be used metal seat, expanding the field of high temperature butterfly valve applications.

Electric double eccentric butterfly valve sealing principle is similar to a single eccentric butterfly valve, which is a sealed structure, that is, the sealing surface of the butterfly plate and the valve seat is in line contact. The elastic deformation caused by squeezing the valve seat of the butterfly plate produces the sealing effect. Therefore, High requirements (especially metal seat), low pressure capacity, it is recommended to use one-way.

Under normal circumstances, the fluid flow from upstream to downstream of the pipeline under the pressure, the valve is closed, the pressure direction of the valve and the medium flow direction, in this case, the pressure direction of the valve is positive pressure. But the nuclear island also has the opposite situation, the valve is closed, the pressure direction is the reverse of the medium flow, is the reverse pressure.