The Advantages and Disadvantages of Gate Valve
Gate valve is a kind of valve that is widely used in pipelines. Its main role is to connect and shut off medium. It’s not suitable for regulating the flow of the medium, but it can judge the amount of flow according to the height of the sanitary valve stem. Compared with other valves, gate valve has a wider range of applications for pressure, temperature and caliber.
According to different internal structure, gate valve can be divided into wedge single gate plate type, elastic gate plate type, double gate plate type and parallel gate plate type.
According to different valve stem stents, gate valve can be divided into rising stem gate valve and non-rising stem gate valve.
The main advantages of gate valve include:
1. The fluid resistance of the valve is small. Because the valve body of gate valve is straight-through type and the flow of the medium doesn’t change direction, the fluid resistance of it is small compared with other kinds of valves.
2. The sealing performance is better than that of the shut-off valve. The opening and closing of it is more convenient than those of the shut-off valve.
3. The range of applications is wide. In addition to steam, oil and other media, it can be used in medium containing granular solid and with a large viscosity. It can also be used as venting valve and low vacuum system valve.
4. Gate valve is a valve that has dual flow directions. It’s not subject to the flow directions of the medium. Therefore, it is suitable for use in pipeline where the medium may change the flow direction. It is also easy to install.
The main disadvantages of gate valve include:
1. The opening and closing time is long. During the opening process, the valve plate needs to be lifted to the upper part of the valve chamber. During the closing process, the valve plate needs to fall into the valve seat. Thus, the opening and closing distance of the valve plate is large, leading to long opening and closing time.
2. Because there is friction during the opening and closing processes between the valve plate of the gate valve and the two sealing surfaces of the valve seat, the sealing surface is prone to scratch, which has an impact on the sealing performance and the service life. And it’s not easy for repair.