Views: 16 Author: Site Editor Publish Time: 2022-04-14 Origin: Site
The disc of the wedge gate valve is wedge-shaped, and the purpose of using the wedge shape is to increase the auxiliary sealing load, so that the metal-sealed wedge gate valve can not only ensure high medium pressure sealing, but also low medium pressure. In this way, a metal-sealed wedge gate valve can achieve a higher potential level of sealing than a common metal-sealed parallel gate valve. However, the inlet sealing load generated by the wedging action of metal-sealed wedge gate valves is often insufficient to achieve inlet sealing.
The valve body of the wedge gate valve is provided with a guiding mechanism, which can prevent the gate from rotating when opening or closing, so as to ensure the corresponding alignment of the sealing surface, and make the disc not rub against the valve seat before reaching the closed position, thereby reducing the sealing surface of wear.
The disadvantage is that the wedge gate valve cannot be provided with a guide hole like a parallel gate valve with a guide hole, and the thermal expansion of the valve stem will also overload the sealing surface. Moreover, the sealing surface of the wedge gate valve is more likely to contain solid particles carried by the flowing medium than the parallel gate valve. But the rubber-sealed wedge gate valve can seal the medium with tiny particles. Like parallel gate valves, wedge gate valves are not suitable for throttling. It is mainly used for occasions with less switching times.
Compared with the parallel gate valve, the electric drive used by the wedge gate valve is more complicated, because the electric drive does not limit the stroke, but the torque. The wedge gate valve must have a large enough closing torque to make the disc wedge the valve seat to seal when the valve is closed. In order to be able to open at full differential pressure and to allow for increased opening and closing torque due to thermal expansion of valve components, the drive must have sufficient torque margin.
More details of wedge gate valves, please go to https://www.mingpinmetals.com/Gate-Valve-pl3117724.html