Globe valve, also known as shut-off valve, belongs to the forced sealing type valve and is a type of shut-off valve. There are three types of connection methods: flange connection, threaded connection, and welded connection. The "Three Modernizations" of valves in our country once stipulated that the flow direction of globe valves should be from top to bottom, so there is directionality during installation.

The globe valve is designed with low inlet and high outlet to reduce flow resistance and save effort when opening the valve. When the valve is closed at the same time, the gasket between the valve shell and valve cover, as well as the packing around the valve stem, are not subjected to force and will not be affected by medium pressure and temperature for a long time. This can prolong the service life and reduce the probability of leakage. In addition, this can also replace or add packing when the valve is closed, making maintenance easier.

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 valves with a diameter greater than 100mm

Due to the poor sealing performance of large-diameter valves, this method is used to increase the sealing performance of the valve by applying medium pressure above the valve disc when the shut-off valve is in a closed state.

2. Two shut-off valves connected in series on the bypass pipeline, the second shut-off valve requires "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 connected globe valves.

3. Boiler exhaust and vent shut-off valves

The boiler exhaust and vent shut-off 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 install such shut-off valves in a "high inlet and low outlet" direction to improve tightness.