Gate valve, also known as gate valve, mainly by the valve body, valve plate, valve cover, valve seat and sealing parts, is one of the most common types of valves in isolation class. The main purpose of a gate valve is to cut off the flow and thus become a stop or stop valve. Gate valves are available in a variety of configurations, with different seal element configurations. According to the structure of the sealing element, it can be divided into different types.
The stem trapezoidal thread of the rising stem gate valve is placed outside the valve body and located in the upper part of the stem. By rotating the stem nut, the stem can drive the valve plate up or down synchronously to realize the opening and closing of the valve. Therefore, it is easy to identify the opening and closing state of the valve and avoid misoperation. Stem nuts are widely used because they are externally lubricated and open and close visually. However, exposed threads in the stem are vulnerable to damage and corrosion in harsh environments, and can even affect operation. Its disadvantage is that the valve opened after the height is large, usually in the original height of the valve on the basis of a stroke, so the need for a large operating space.