Gate Valve Movement Mode

When the gate valve is closed, the sealing surface can be sealed only by the medium pressure, that is, the sealing surface of the gate plate is pressed to the valve seat on the other side by the medium pressure only to ensure the sealing of the sealing surface. This is self-sealing. Most gate valves adopt forced sealing, that is, when the valve is closed, external force must be relied on to force the gate plate to the valve seat to ensure the sealing performance of the sealing surface.
Movement mode: The gate plate of the gate valve moves linearly with the valve stem, which is also called a rising stem gate valve. Usually there is a trapezoidal thread on the lift rod, and through the nut on the top of the valve and the guide groove on the valve body, the rotating motion is changed into linear motion, that is, the operating torque is changed into the operating thrust. When the valve is opened, when the lift height of the gate plate is equal to 1:1 times of the valve diameter, the fluid channel is completely unobstructed, but during operation, this position cannot be monitored. In actual use, the top of the valve stem is used as a mark, that is, the position that does not open, as its fully open position. In order to consider the locking phenomenon due to temperature changes, the valve is usually opened to the top position and then retracted 1/2-1 turn as the fully open valve position. Therefore, the fully open position of the valve is determined by the position of the gate plate (i.e. stroke). Some gate valve stem nuts are set on the gate plate, and the rotation of the handwheel drives the valve stem to rotate, thereby lifting the gate plate. This kind of valve is called Rotating rod gate valve or hidden rod gate valve.