Applications of Eccentric Cylindrical Plug Valves with Elastic Seats

The elastic seat seal eccentric plug valve has excellent corrosion resistance and sealing performance, and its service life and reliability are much better than traditional partial rotary valves due to its eccentric design, stainless steel or pure nickel overlay welding valve seat, and the overall rubber-covered cock. Therefore, this valve is an ideal upgrade product of traditional plug valves and hemispherical valves, especially suitable for industrial sewage, urban sewage, mud and media with high solid content. It is currently used in sewage treatment and other industrial systems in developed countries such as the United States, Germany and Italy.
 
If the elastic seated eccentric plug valve is used in the clean water pipeline system, its installation method can be vertical or horizontal. In the raw water and sewage system, the plug valve must be installed horizontally, so that the axis of the cock is in the vertical direction, and the operating device is guaranteed to be above, so that when the plug valve is opened, the cock will not be blocked or scratched by impurities sinking to the bottom. In addition, if impurities are deposited at the bottom of the valve body, when the cock is in the throttling adjustment state, the impurities are easy to be flushed due to the high flow rate of the medium. For clean water, the installation direction of the valve should be positive, that is, the valve seat is opposite to the direction of the fluid. If the fluid contains solid and depositable particles, it should be given priority to install the valve axis in a horizontal direction, that is, on a horizontal pipeline. If the valve is opened, the cock should be at the top of the horizontal pipeline; on a vertical pipeline, if the valve is closed, the cock should be at the top.
 
The plug valve can be installed forward or reverse, and the position of the fluid and the valve determines the installation direction of the valve. The ability of the plug valve to withstand reverse pressure is limited due to the eccentric sealing structure, and only the positive sealing performance is guaranteed under normal circumstances.
 
The straight-through channel of the eccentric plug valve with elastic seats makes the loss of fluid head small. Under the same flow rate, the pressure loss of the plug valve is the smallest, and the energy consumption is the lowest. This advantage becomes more obvious as the diameter of the valve increases. The rectangular cross-section of the elastic seated eccentric plug valve can obtain ideal linear flow regulation, and the driving mode of the valve can be equipped with electric, pneumatic or hydraulic devices to realize automatic control.
 
For example, the elastic seated eccentric plug valve can be used as a pump outlet control valve, which has the functions of preventing backflow, preventing water hammer and regulating flow. When the pump is started, the valve is gradually opened, and the flow output increases slowly, which is not easy to cause water hammer and damage the equipment on the system. When the pump is closed, close the valve first, and then stop the pump, which can provide segmental closure, and the control valve can be synchronized with the closing of the pump to prevent water hammer caused by backflow of water. By using the flow regulating and blocking of the plug valve, the water delivery volume of the pipeline can be adjusted according to the management needs. The eccentric plug valve with elastic seats is a new type of plug valve. It is used as a pipeline adjustment or shut-off device and has been widely used in urban sewage, industrial sewage, mud and clean water and other occasions.