How does the gate valve work?

How does the gate valve work?

Working principle of gate valve:

Gate valve can only be fully opened or fully closed, and cannot be used as a valve for regulating flow. Its working principle is that the gate with the stem to rise and fall to do linear motion, the valve stem has trapezoidal thread, through the nut at the top of the valve and the valve body on the guide groove, to achieve the up and down movement of the valve stem, the valve stem drives the motion of the gate. The direction of motion of the ram is perpendicular to the direction of the pipeline fluid medium.

The fully open status of gate valves cannot be viewed during operation, especially for dark stem gate valves. The opening state of the open rod gate valve can be judged by observing the exposed stem position. The dark rod gate valve is generally regarded as a sign that it is fully opened until it cannot be opened. But considering the possibility of locking due to temperature change, the general gate valve is opened to the end, that is, when the opening position is not moving, and then about 1/2 turn, as the gate valve fully open position.

After the gate valve is closed, there can be self-sealing and forced sealing in two forms, self-sealing means that the sealing surface can only rely on the medium pressure to seal. But most of the gate valves are forced to seal, that is to say, when the gate valve is closed, it is necessary to rely on external force to force the gate to the seat, to ensure the sealing performance of the sealing surface. Usually the sealing performance of gate valve is better than that of butterfly valve.