Globe Control Valves

Internal view of globe control valve (Masoneilan)

Globe control valves work differently when compared to gate valves, ball valves, butterfly valves and plug valves in process control applications. They are primarily used to control the flow inside pipes, and are popular in a wide variety of industries. Globe control valves are ideal in situations where precise control is required. They are used to regulate flow in pipelines with a high degree of accuracy by regulating a pressures drop created in the valve body that allows the fluid to pass through the passageway (port) in the valve body. The control valve stem provides linear motion to bi-directionally control flow, opening and closing the valve by changing the distance between valve disc and seat. The flow in the pipeline changes according to the position of the disc lifting from the seat. The movement is controlled through the use of manual operators, or through the use of electric or pneumatic actuators.

Applications of Globe Control Valves 

Globe control valves are used in many different industries, but particularly in the petrochemical and power generation industries on fuel oil pipes, chemical feed systems, steam pipes, as well as cooling water and feedwater systems.  Other industrial applications of globe valve include boiler, main steam vents, and turbine lube oil systems.

Pros

Globe control valves have many advantages that make them preferable over other valve designs. Globe control valves have excellent shut-off and throttling capabilities. In addition, globe valves are easy to maintain and repair compared to other valves.

Cons

Globe control valves have also certain shortcomings. For instance, globe valves have an S-shaped flow pattern (as opposed to a straight-through flow pattern) which creates a significant pressure drop making them unsuitable for applications constant pressure is required.  Another shortcoming of the globe valves is they generally require greater torque to open and close, requiring larger actuators to properly seat the valve.

For more information on industrial globe valves, or any type of industrial valve, contact Classic Controls by calling 863-644-3642 or by visiting https://classiccontrols.com.

When to Use a Globe Valve for Fluid Process Control

Heavy duty industrial globe valve with pneumatic actuator
Masoneilan brand of GE

Industrial process control often involves the regulation of fluid flow. There are almost uncountable types and variants of flow control valves, each with a particular set of attributes that can make it the advantageous choice to meet certain applications.

When the process calls for controlling flow over a range of possible values, known as throttling, a globe valve may be a good candidate for the application.

Globe valves are characterized by the change in direction of fluid flow as it passes through the valve and the plug or disk positioned in an opening through which fluid must pass. The plug is connected to a stem extending to the exterior of the valve body through the bonnet. Movement of the stem will reposition the plug in relation to the opening, providing a successively larger or smaller opening area through which fluid can pass.

Simple globe valve diagram
Courtesy Wikipedia

Globe valves are available in tee, angle, and wye configurations, as well as an enormous range of special configurations to suit specific applications.

What are some potential advantages of globe valves?

• Good throttling and shutoff capability
• Comparatively easy maintenance
• Comparatively short travel of plug from open to closed position
• Seats can usually be resurfaced when worn

What are some limiting factors for globe valves?

• Higher valve pressure drop than some other designs
• No straight through fluid path
• Comparatively higher actuator torque requirements to operate valve

When flow throttling capability is the overriding concern for an application, a globe valve could be a good candidate for consideration. Share your flow control challenges with product specialists. Combining your process knowledge with their product application expertise will produce effective solutions.