Among various types of valves, gate valves are the most […]
Among various types of valves, gate valves are the most widely used. Gate valve means that the closing element (gate) is mainly used as a cutting medium along the channel, that is, fully open or fully closed. General gate valve can not be used as throttle. It can be used for high temperature and high pressure, and can be used for various media. Gate valves are generally not used in pipelines for inputting mud and viscous fluids. The gate of the gate valve moves linearly with the valve stem, which is called the lift rod gate valve (also known as the open rod gate valve). There is usually a trapezoidal thread on the lifting rod. The nut moves from the top of the valve and the guide groove on the valve body to change the rotary motion into linear motion, that is, the operating torque into the operating thrust. In some valves, the stem nut is set on the gate, and the rotation of the hand wheel drives the stem to rotate, and the gate is lifted. This kind of valve is called a rotary rod gate valve or a dark rod gate valve.
Gate valve has the following advantages:
1. Low fluid resistance;
2. The torque required for opening and closing is small;
3. Can be used in the ring network pipeline where the medium flows in two directions, that is to say the flow direction of the medium is not restricted;
4. When fully open, the erosion of the sealing surface by the working medium is smaller than that of the globe valve;
5. The shape is relatively simple and the manufacturing process is good;
6. The structure length is small;
Because gate valves have many advantages, they are widely used. Usually the pipeline with nominal size ≥ DN50 is used as the device to cut off the medium. Gate valves are used. Even on some official roads with small diameters, some gate valves are still reserved.