Working principle and characteristics of shut-off valves

Valves play an important role in cutting off and throttling the medium in the pipeline they are in. As an extremely important type of cut-off valve, globe valves are sealed by applying torque to the valve stem. The valve stem exerts pressure on the valve disc in the axial direction, making the sealing surface of the valve disc tightly adhere to the sealing surface of the valve seat, and preventing medium leakage along the gap between the sealing surfaces.

The sealing pair of the shut-off valve consists of the sealing surface of the valve disc and the sealing surface of the valve seat. The valve stem drives the valve disc to move vertically along the centerline of the valve seat. During the opening and closing process of the shut-off valve, the opening height is small, making it easy to adjust the flow rate, and it is easy to manufacture and maintain, with a wide range of pressure applications.

Compared with another commonly used shut-off valve in industrial production, gate valve, in terms of structure, shut-off valve is simpler and easier to manufacture and maintain. In terms of service life, the sealing surface of the globe valve is not easy to wear and scratch. During the valve opening and closing process, there is no relative sliding between the valve disc and the sealing surface of the seat, so the wear and scratch on the sealing surface are relatively small. Therefore, the service life of the sealing pair is improved. During the full closing process, the valve disc travel of the globe valve is small, and its height is relatively small compared to the gate valve. The disadvantage of a shut-off valve is that it has a large opening and closing torque and is difficult to achieve rapid opening and closing. Due to the tortuous flow channels in the valve body, the fluid flow resistance is high, resulting in significant loss of fluid power in the pipeline.