Working principle of Globe valve

working principle

Globe valve, also known as cut-off valve, is one of the most widely used valves. The reason why it is popular is that the friction between the sealing surfaces is small during the opening and closing process, it is more durable, the opening height is not large, and it is easy to manufacture. , easy maintenance, not only suitable for medium and low pressure, but also suitable 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 disc and the sealing surface of the valve seat closely fit to prevent the flow of the medium. my country's valve "Three Chemicals" once stipulated that the flow direction of the globe valve shall be from top to bottom, so there is directionality during installation. The structure of the globe valve is longer than that of the gate valve, and at the same time, the fluid resistance is large, and the sealing reliability is not strong during long-term operation.

As one of the most important shut-off valves, the globe valve plays an important role in the aerospace field. As an important component of aerospace equipment, globe valve realizes the functions of medium transportation, cutoff and adjustment, and its sealing performance directly affects the safe and reliable operation of aerospace equipment. The study of the influencing factors and influence rules of the sealing characteristics of typical globe valves has guiding significance for the structural design of the valve sealing pair, thereby improving the sealing performance and reliability of the valve.

Globe valve working principle and characteristics

The valve plays an important role in cutting off and throttling the medium in the pipeline where it is located. As an extremely important cut-off valve, the globe valve is sealed by applying torque to the valve stem, and the valve stem moves upward in the axial direction. The disc applies pressure to make the sealing surface of the disc and the sealing surface of the valve seat closely fit, preventing the medium from leaking along the gap between the sealing surfaces.

The sealing pair of the globe valve is composed of the sealing surface of the valve disc and the sealing surface of the valve seat, and the valve stem drives the valve disc to move vertically along the center line of the valve seat. During the opening and closing process of the globe valve, the opening height is small, it is easy to adjust the flow, and it is convenient to manufacture and maintain, and the pressure is applicable to a wide range.

Compared with the gate valve, another commonly used cut-off valve in industrial production, the cut-off valve is simpler in structure 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, and there is no relative sliding between the valve disc and the sealing surface of the seat during the opening and closing process of the valve, so the wear and scratches on the sealing surface are small, so the sealing performance is improved. The service life of the auxiliary globe valve is small in the process of full closing, and its height is smaller than that of the gate valve. The disadvantage of the globe valve is that the opening and closing torque is large and it is difficult to achieve rapid opening and closing. Because the flow channel in the valve body is relatively tortuous, the fluid flow resistance is large, resulting in a large loss of fluid power in the pipeline.