As the principle of the valve is what kind of valve and another name is the door, it is a widely used but also a number of valve products in. It's popularity is due to its many advantages in opening, the sealing surface friction is small, durable process, long service life, flexible opening and closing, simple and reasonable structure, easy maintenance, not only can be used in low pressure, at high pressure can also make use of safety. The closure principle of the cut-off valve is to rely on the pressure of the valve bar to close the valve seal face closely with the seat sealing surface to prevent the circulation of the medium. The globe valve has a relatively simple flow medium. It can only accept the unidirectional flow of the medium. It is also directional when installed, and its fluid resistance is relatively large. If it works for a long time, its sealing reliability is not strong enough.