Is the shutoff valve low in and high out?

In discussing how globe valves work, we first need to understand a basic physical concept: the direction of fluid flow. In most cases, globe valves are designed to operate in a low-in, high-out mode, where the fluid flows in from the bottom of the valve and out from the top. This design is primarily based on the natural flow characteristics of the fluid and the operating mechanism of the globe valve.

Why are globe valves low inlet and high outlet?
1. Natural flow characteristics: In the absence of an external force, a fluid, such as water or gas, will tend to flow from an area of lower pressure to an area of higher pressure. The low-in/high-out design takes advantage of this property by allowing the fluid to flow in through the inlet (lower pressure section) and out through the outlet (higher pressure section).
2. Operating Mechanism: The operation of a globe valve depends on the fit between the stem and the seal. The low inlet and high outlet design allows the fluid to build up a certain pressure above the sealing ring, helping to seal and prevent fluid leakage.
3. Maintenance and Installation: The low-in, high-out design makes globe valves easier to maintain and install. Because the fluid flows in the same direction as gravity, the fluid flows more smoothly, reducing the possibility of blockage and wear.

When is a globe valve high inlet and low outlet?
Although in most cases globe valves are low inlet and high outlet, a high inlet and low outlet design may be utilized in certain situations, such as when fluid needs to be injected from above or when it is necessary to prevent fluid from clogging the piping under the influence of gravity. For example, in some vertically mounted piping, a high inlet and low outlet design may be chosen to prevent fluid from blocking the piping under the influence of gravity. In addition, some special applications, such as in the chemical or petroleum industries, may utilize a high inlet and low outlet design due to specific process requirements.
Globe valves are initially designed to realize a low-in, high-out operating mode, which is in line with the natural flow characteristics of fluids and operating mechanisms. However, in some special application scenarios, a high inlet and low outlet design may be used to meet specific needs, such as to prevent blockage or to meet specific process requirements.