Globe Valve - its Uses and Design

Inside this round body, is the valve seat and disc, set up at a right angle to the axis of the valve. The vertical movement of the disc, in other words, away from the valve seat – causes a space between the disc and disc ring, responsible for opening the valve.
This structure of the valve provides an excellent throttling ability to the globe valve, which helps regulate the flow of the liquid. The valve is used not only to start and stop the flow of the fluid but also for regulating it. There are three types of designs of the globe valve:
Z-body design
Y-body design
Angle design
Z-Body Design

The most common design of the valve, this type of design is most preferred for governing the flow of water. As the name suggests, the globe-shaped body has a partition that is z shaped. The stem and the disc move at a right angle to the body of the valve, aligning with the horizontally arranged seat. The stem passes through the bonnet that is attached to a wide opening at the top.

Y-Body Design

This type of valve design is useful in situations where the pressure drops, a challenge commonly found in globe valves. As shown in the image, the valve seat and stem are angled at roughly 45 degrees to the valve’s axis. As a result, it provides a straight path for the liquid to flow, creating a pressure-resistant environment within the valve.

These types of valves are suited for high-pressure applications wherein challenges related to pressure drop are usual.

Angle Design

This design is a modification of the z shaped design. As seen in the diagram, the fluid flows through the valve body in a right-angled flow path. This is key in situations that involve a high pressure of fluids. However, in the case of moderate conditions, the valve functions just like a z shaped design.

Globe valves are used for both low and high-temperature situations. In case of low temperature, the globe valves are installed so that the pressure is under the disk. This allows the valve to operate with ease and prevents the seat and disc from erosion.
In case of high temperatures, the valves are installed so that the pressure is above the disc. This prevents the steam below the disc from contracting when it cools down and lifts the disc off the seat.