Gate valves are the most widely used of all types of valves.Gate valve refers to the closing parts (gate) along the channel mainly as cutting medium, that is, full open or full closed use.General gate valves should not be used for throttling.It can be used at high temperature and high pressure, and can be used in a variety of media.Gate valves are generally not intended for use in mud or viscous fluid lines.The disc of a gate valve moves in a straight line with the stem, called a lifting stem gate valve (also known as a rising stem gate valve).Usually there is a trapezoidal thread on the lifting rod, through the nut at the top of the valve and the guide groove on the valve body, to change the rotation motion to a straight line, that is, to change the operating torque to the operating thrust.Some valves, stem nuts located in the gate, handwheel rotation drives the stem rotation, which causes the gate to lift, such valves are called rotary stem gate valves or dark stem gate valves.Gate valves have the following advantages:
1. Low fluid resistance;
2. Small torque required for opening and closing;
3. It can be used in the loop network management road where the medium flows in two directions, that is, the flow direction of the medium is not restricted;
4. When fully open, the sealing surface is less eroded by working media than the globe valve;
5. The shape is relatively simple and the manufacturing process is good;
6. Small structure length;
Because gate valves and have many advantages, so the use of a wide range.Usually, the pipeline with nominal size ≥DN50 is used as the device for cutting medium. Even in some small-bore official roads, some gate valves are still retained at present.