Welded stop valve A flat, or straight-line, plug-in valve that moves along the center of the seat. It can be used to control various types of fluids such as air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive medium. Therefore, this type of Globe valve The globe valves are suitable for cutting or to adjust and throttle valves. Due to the relatively short opening or closing stroke of such a valve stem, but very reliable cut-off function, and because of the change in the proportional relationship between the valve seat and the valve opening, it is very suitable for the flow regulation.
Welded globe valve structure, also known as shut-off valve, belongs to the national compulsory sealing design valve, so when the valve is automatically closed, a certain pressure must be applied to the valve disc to force the sealing surface not to leak. When the medium starts to enter a valve from the bottom of the valve disc, the resistance that we need to overcome is the friction between the valve stem and 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 diameter of the valve stem is large, otherwise the valve stem will be bent. According to the connection management mode, it is mainly divided into the following three types: flange connection, screw connection and welding technology connection. Since the emergence of self sealing valve enterprises, the medium flow direction of the globe valve changes from the upper part of the valve disc to the valve cavity. Under the influence of the medium working pressure, the force to close the valve is small, but the force to open the valve is large. The diameter of the valve stem can be reduced correspondingly. At the same time, under the interaction of media, the valve of this teaching form is also more strict. In China, the "top-down" valve was used. When the stop valve is opened, the opening height of the disc is 25% - 30% of the nominal large diameter. The flow level has reached a large value, indicating that the number of control valves has reached the full open position. Therefore, the full opening or position of the two stop valves should be determined by the stroke of the disc.