Wednesday, August 10, 2016

When to Use a Globe Valve for Fluid Process Control

heavy duty industrial control globe valve with pneumatic actuator
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.
diagram of globe valve
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.