There are three types of connection methods: flange connection, screw connection, and welding connection. The "three modernizations" of valves in our country once stipulated that the flow direction of shut-off valves should be from top to bottom, so there is directional installation. The movement form of the valve stem, commonly known as the non rising stem, has a lifting and rotating rod type, which can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, mud, oil, liquid metal, and radioactive media. Therefore, this type of shut-off valve is very suitable for cutting, regulating, and throttling purposes. Due to the relatively short opening or closing stroke of the valve stem and the highly reliable cut-off function, as well as the proportional relationship between the change of the valve seat opening and the stroke of the valve disc, this type of valve is very suitable for regulating flow.

The shut-off valve is designed for low inlet and high outlet, with the aim of reducing flow resistance and saving effort when opening the valve. When the valve is closed at the same time, the gasket between the valve shell and valve cover and the packing around the valve stem are not subjected to force, which can prolong the service life and reduce the probability of leakage by not being subjected to medium pressure and temperature for a long time. In addition, this can also replace or add packing when the valve is closed, making maintenance easier.

Many people believe that shut-off valves are low in and high out, but in fact, they are not. In general, globe valves are low in and high out, but there are also some special cases where globe valves are high in and low out:
1. High pressure shut-off valve with a diameter greater than 100mm
Due to the poor sealing performance of large diameter valves, when using this method to stop the valve in the closed state, the medium pressure acts on the valve disc to increase the sealing performance of the valve.
2. Two shut-off valves connected in series on the bypass pipeline, with the second shut-off valve requiring "high inlet and low outlet"
To ensure the tightness of the valve within a maintenance cycle, valves that frequently open and close require the installation of two series shut-off valves. For the bypass system, the installation function of this bypass includes: ① balancing the pressure before and after the main pipeline valve, making opening convenient and labor-saving, and reducing the wear of the main pipeline valve; ② Warm up pipes with small and medium flow during startup; ③ On the main water supply pipeline, control the water flow to control the boiler pressure increase speed for boiler water pressure test. The bypass shut-off valves are divided into primary and secondary valves according to the direction of medium flow. During normal operation of the unit, the primary and secondary valves are closed and both come into direct contact with the medium. To prevent the gasket between the secondary valve shell and valve cover, as well as the packing around the valve stem from being subjected to medium and temperature effects for a long time, and to replace the valve packing during operation, the installation direction required for the secondary valve is "high in and low out".
3. Boiler exhaust and vent stop valves
The boiler exhaust and vent stop valves are only used during the water supply process during boiler startup, with a small opening and closing frequency. However, they often cause fluid loss due to poor sealing. Therefore, some power plants have installed these stop valves in a "high inlet and low outlet" direction to improve their tightness.
4. Electromagnetic quick break valve
The function of the electromagnetic quick disconnect valve is to quickly close and cut off the fuel supply. The structure of an electromagnetic quick break valve is similar to that of a globe valve. If the electromagnetic quick break valve also has working fluid flowing in from the bottom and out from the top, the force of fuel acting on the lower part of the electromagnetic quick break valve disc is large, and the weight of the electromagnetic quick break valve is much smaller than it. Therefore, if the working fluid enters the quick break valve from the bottom, the torque generated by the heavy hammer is less than the torque generated by the fuel pressure, and the fuel cannot be cut off when the quick break valve acts, thus the expected purpose cannot be achieved. If the working fluid enters from the upper part of the quick break valve, due to the rapid decrease in pressure behind the valve once the quick break valve acts, the force of fuel acting on the lower part of the valve disc quickly decreases to zero, while the force of fuel acting on the valve disc and the force formed by the gravity of the hammer and lever.

It is difficult to close the valve when using low inlet and high outlet in general large caliber and high-pressure conditions. If using low inlet and high outlet in high-pressure large caliber conditions, the valve stem is prone to deformation and bending due to long-term water pressure, which affects the safety and sealing of the valve; Choosing a high inlet and low outlet can reduce the diameter of the valve stem, which will also save some costs for manufacturers and users.