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  • sanitary cut-off valve
  • sanitary cut-off valve
  • sanitary cut-off valve
  • sanitary cut-off valve
sanitary cut-off valve sanitary cut-off valve sanitary cut-off valve sanitary cut-off valve

sanitary cut-off valve

 Stop valve, also known as shut-off valve, is a forced sealing valve, so when the valve is closed, pressure must be applied to the disc to prevent leakage of the forced sealing surface. When the medium enters the valve from below the valve disc, the resistance to be overcome by the operating force is the friction between the stem and packing and the thrust generated by the pressure of the medium. The force to close the valve is larger than that to open the valve, so the diameter of the stem should be larger, otherwise the stem will be bent. According to the connection mode, it can be divided into three types: flange connection, screw connection and welding connection. After the appearance of self sealing valve, the medium flow direction of the stop valve will change from the top of the disc to the valve chamber. Under the action of medium pressure, the force to close the valve is small, while the force to open the valve is large, and the diameter of the stem can be reduced accordingly. At the same time, under the action of medium, this type of valve is also tight. China's valve "three to" has stipulated that the flow direction of the stop valve, all adopt top-down. When the stop valve is opened, when the opening height of the disc is 25% - 30% of the nominal diameter, the flow has reached the maximum, indicating that the valve has reached the full open position. Therefore, the full open position of the globe valve should be determined by the stroke of the disc.
 
The stop valve (globe valve) is a plug-in disc, which is flat or conical on the sealing surface. The disc moves along the center line of the valve seat in a straight line. It can be used to control the flow of air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive media. Therefore, this type of shut-off valve is very suitable for cut-off or regulation and throttling. Because the opening or closing stroke of the valve stem is relatively short, and it has a very reliable cut-off function, and because the change of the valve seat opening is directly proportional to the stroke of the valve disc, it is very suitable for regulating the flow.
 
Stop valve, also known as shut-off valve, is one of the most widely used valves. Its popularity is due to the small friction between sealing surfaces in the process of opening and closing, relatively durable, small opening height, easy manufacturing and convenient maintenance. It is not only suitable for medium and low pressure, but also suitable for high pressure. The closing principle of the stop valve is to make the sealing surface of the valve disc and the sealing surface of the valve seat close together by relying on the pressure of the valve rod to prevent the medium from flowing. China's valve "three to" has stipulated that the flow direction of the stop valve, all use top-down, so the installation direction. The structural length of the stop valve is larger than that of the gate valve, and the fluid resistance is large, so the sealing reliability is not strong in long-term operation.
 
As one of the most important cut-off valves, globe valve plays an important role in aerospace field. As an important component of aerospace equipment, the stop valve realizes the functions of medium transportation, stop and adjustment, and its sealing performance directly affects the safe and reliable operation of aerospace equipment. The research on the influencing factors and rules of the sealing characteristics of typical stop valves has guiding significance for the structural design of the valve sealing pair, so as to improve the sealing performance and reliability of the valve
 
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 sealing of the stop valve is to apply torque to the valve stem, and the valve stem applies pressure to the valve disc in the axial direction, so as to make the sealing surface of the valve disc fit closely with the sealing surface of the valve seat, and prevent the medium from leaking along the gap between the sealing surfaces.
 
The sealing pair of stop valve is composed of disc sealing surface and seat sealing surface. The stem drives the disc to move vertically along the center line of the seat. In the process of opening and closing the stop valve, the opening height is small, the flow rate is easy to adjust, the manufacture and maintenance are convenient, and the pressure application range is wide.
 
Compared with 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 stop valve is not easy to be worn and scratched, and the valve disc is not easy to be damaged in the process of valve opening and closing_ There is no relative sliding between the sealing surfaces of the block, so the wear and scratch of the sealing surface are small, so the service life of the sealing pair is improved. In the process of full closing, the valve disc stroke is small, and its height is relatively small. The disadvantage of the stop 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 more tortuous, the fluid flow resistance is large, resulting in greater loss of fluid power in the pipeline.

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