The globe valve, also known as the cut-off valve, is the most widely used valve. The reason why it is popular is because the friction between the sealing surfaces is small during the opening and closing process, which is more durable, the opening height is not large, the manufacturing is easy, and the maintenance is convenient. Not only for medium and low pressure, but also for high pressure. The closing principle of the globe valve is to rely on the pressure of the valve stem to make the sealing surface of the valve stem and the sealing surface of the valve seat closely fit together to prevent the circulation of the medium.

         
For the shut-off valve, not only the installation and maintenance, but also the operation, the operation method is as follows:
1. The opening and closing globe valve should be stable and not impacted. Some parts of the high-pressure shut-off valve with shock opening and closing have considered that this kind of impact force can not be equal to the general shut-off valve.
2. When the globe valve is fully opened, the handwheel should be reversed a little to tighten the threads tightly to avoid loosening and damage.
3. When the pipeline is initially used, there are many internal dirts. You can open the shut-off valve slightly, use the high-speed flow of the medium to flush it away, then gently close and open again, repeat this many times, flush out the dirt, and then put it into normal jobs.
4. Normally open globe valves may have dirt on the sealing surface. When closing, use the above method to flush them out, and then formally close them.
5. If the hand wheel and handle are damaged or lost, they should be equipped immediately, and can not be replaced by an active wrench, so as to avoid damage to the valve stem and the opening and closing failures, so as to avoid accidents in production.
6. Some media are cooled after the shut-off valve is closed, causing the valve to shrink, and the operator should close it again at an appropriate time so that the sealing surface does not leave fine slits, otherwise, the medium flows through the fine slits at high speed, and it is easy to erode the seal surface.
7. During operation, if you find that the operation is too laborious, you should analyze the reason. If the packing is too tight, it can be properly relaxed. If the valve stem is skewed, personnel should be notified to repair it. In some shut-off valves, when the closing state is closed, the closing part is heated and expanded, which makes it difficult to open; if it must be opened at this time, the valve cover thread can be loosened half a circle to eliminate the valve stem stress, and then the hand wheel is turned.
Therefore, the valve plays an important role in cutting off and throttling the medium in the pipeline.