Globe valve, also known as shutoff valve, belongs to forced sealing valve, so when the valve closes, pressure must be exerted on the disc to force the sealing surface not to leak. When the medium enters the valve from bottom of the 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 greater than that is to open the valve, so the diameter of the valve stem is larger, otherwise the failure of the top bending of the valve stem will occur. There are three kinds of connection modes: flange connection, thread connection and welding connection.
The opening and closing parts of the globe valve are plug-shaped discs with flat or conical seals on the top of the seal. The disc moves in a straight line along the center line of the seat. The movement form of the valve stem (common name: concealed rod) can also be used to control the flow of air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive media. Therefore, this type of cut-off globe valve is very suitable for cutting off or regulating and throttling. Because the stem opening or closing stroke of this kind of valve is relatively short, and has a very reliable cut-off function, and because the change of the seat opening is proportional to the disc travel, it is very suitable for flow regulation.
11. Hinge pin