CONTROL VALVE TYPES  

According to control valve structure and construction, the types of control valve as shown n below figure 1.1     

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figure 1.1control valve types

*According to the control valve type theory there were many other types of control valves, but mainly the control valve divided into this type.

CONTROL VALVE PARTS

A control valve consists of two main parts 
  • Actuator
  • Body
Control valve parts

  • Positioner
  • Actuator
  • Spring: Valve spring connect with diaphragm. it opposes air pressure-the force on the diaphragm to control and also back up to original position when air pressure relies  
  • Diaphragm: Diaphragm is a flexible component that flexes in response to the pneumatic signal sent by the controller. 
  1. Stem 
  2. Yoke
  3. Valve body
  4. Plug
  5. Plug seat 
  6. Feedback link 
  7. Scale(0 to 100%): To determine position of control valve. generally, it is in percentage(%)
  8. Indicating edge
  9. Gland nut
  10. Gland packing 
  11. Bonnet
  12. Cage
  13. 3 num of gauge