Control valves

Control valves are valves used within industrial plants and elsewhere to control operating conditions such as temperature, pressure, flow, and liquid level by fully or partially opening or closing in response to signals received from controllers that compare a "setpoint" to a "process variable" whose value is provided by sensors that monitor changes in such conditions.^[1]

Additional recommended knowledge

Weighing the right way

Safe Weighing Range Ensures Accurate Results

Daily Sensitivity Test

The opening or closing of control valves is done by means of electrical, hydraulic or pneumatic systems.

Types of control valve bodies

The different types of control control valve bodies may be categorized as shown below:^[2]  

• Globe Valves
  • Single-Port Valve Bodies
  • Balanced-Plug Cage-Style Valve Bodies
  • High Capacity, Cage-Guided Valve Bodies
  • Port-Guided Single-Port Valve Bodies
  • Double-Ported Valve Bodies
  • Three-Way Valve Bodies
• Rotary Valves
  • Butterfly Valve Bodies
  • V-Notch Ball Control Valve Bodies
  • Eccentric-Disk Control Valve Bodies
  • Eccentric-Plug Control Valve Bodies

See also

• Control engineering
• Control system
• Instrumentation
• Instrumentation engineering
• Process control

References

• Control Valve Handbook (4th Edition) A complete 297-page online book.

• Process Instrumentation (Lecture 8): Control valves Excellent article from a University of South Australia website.