manual flange ammonia special stainless steel globe valve

Globe valve, also known as cut-off valve, is a mandatory sealing valve, so when the valve is closed, pressure must be applied to the valve disc to force the sealing surface not to leak. When the medium enters the valve from under the valve disc, the resistance that the operating force needs to overcome is the friction force between the valve stem and the packing and the thrust generated by the pressure of the medium. The force to close the valve is greater than the force to open the valve, so the valve stem The diameter of the valve should be large, otherwise the failure of the top of the valve stem will occur. According to the connection method, it is divided into three types: flange connection, thread connection and welding connection. After the appearance of the self-sealing valve, the medium flow direction of the globe valve is changed from the top of the valve disc into the valve cavity. At this time, under the action of the medium pressure, the force to close the valve is small, but the force to open the valve is large, and the diameter of the valve stem can be adjusted accordingly. decrease. At the same time, under the action of the medium, this form of valve is also tighter. my country's valve "Three Chemicals" once stipulated that the flow direction of the globe valve should be from top to bottom. When the globe valve is opened, the opening height of the valve disc is 25% to 30% of the nominal diameter. The flow rate has reached the maximum, indicating that the valve has reached the fully open position. Therefore, the fully open position of the globe valve should be determined by the stroke of the valve disc.
The opening and closing part of the stop valve (Globe Valve) is a plug-shaped valve disc. The movement form of the valve stem, (common name: dark rod), also has a lifting and rotating rod type, which can be used to control various types of fluids such as air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive media. flow. Therefore, this type of shut-off globe valve is very suitable for shut-off or regulation and throttling. Because the valve stem of this type of valve has a relatively short opening or closing stroke, and has a very reliable cut-off function, and because the change of the valve seat port is proportional to the stroke of the valve disc, it is very suitable for flow regulation.
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