What is the working principle of the gate valve? What are the advantages and disadvantages?

Gate valve: also called gate valve, gate valve, is a widely used instrument valve.

Working principle: The sealing surface of the ram and the sealing surface of the valve seat are smooth, flat and consistent, and processed into a very close and tight sealing pair. The gate is turned on and off by the lifting and lowering of the valve stem to form a turn-on and turn-off of the medium. It acts as a shut-off in the pipeline.

Advantages: The fluid resistance is small; the sealing surface is not eroded when fully open; it can be used in the case of two-way flow of the medium, no directionality; strong and durable; not only suitable for small instrument valves, but also for large instrument valves.

Disadvantages: high height; long opening and closing time; cumbersome; difficult to repair; if it is a large diameter gate valve, manual operation is more laborious.

The gate valve is divided into the rod type and the dark rod type according to the different stems; the parallel structure and the wedge type according to the structure of the gate; and the division of the single gate and the double gate. In the heating project, the common-wing wedge type single gate valve (Z41H-16C) and the dark-rod wedge type single gate valve (Z45T-10) are used. The former is installed on the primary side of the heat station, and the latter is installed in the heat station. Secondary side. It generally serves two purposes: as a master device to act as a switch; as an auxiliary device for maintenance before and after the master device.

When installing the gate valve, do not place the handwheel below the horizontal line (flip), otherwise the medium will remain in the valve cover for a long time, which will easily corrode the valve stem. In the heating project, the gate valve used to be the main force in the instrument valve. Now with the widespread adoption of butterfly valves, gate valves have been replaced by butterfly valves.