Different types of control valves

Different Types of Control valves

1. DIFFERENT TYPES OF CONTROL
VALVES
 
Prem Baboo
Sr. Manager (Prod)
National Fertilizers Ltd. India
F.I.E., Institution of Engineers (India)
Technical Advisor & an Expert for
www.ureaknowhow.com

2. CONTENTS
•INTRODUCTION
•CLASSIFICATION
•CONTROL VALVE PARTS

5. CONTROL VALVE ?CONTROL VALVE ?
•A VALVE WITH ACTUATOR THAT
AUTOMATICALLY, FULLY OR PARTIALLY
OPENS OR CLOSES THE VALVE TO A
POSITION DICTATED BY SIGNALS
TRANSMITTED FROM CONTROLLING
INSTRUMENTS CAN BE CALLED AS A
CONTROL VALVE

8. CLASSIFICATION
•CONTROL VALVES ARE
CLASSIFIED ACCORDING TO
–BODY TYPES
–CHARACTERISTICS

9. BODY TYPES
•GLOBE VALVES
•BUTTERFLY VALVES
•BALL VALVES
•DIAPHRAGM VALVES
•ANGLE VALVES

11. GLOBE VALVE CONSTRUCTION
SEAT
PLUGSTEM

12. GLOBE VALVE

13. 3 WAY
DOUBLE
SEATED

14. BUTTERFLY VALVE

17. BALL VALVE

18. BALL
SEATS
BALL VALVE INTERNALS

21. DIAPHRAGM VALVE

22. DIAPHRAGM VALVE

23. ANGLE VALVE

25. Valve Body Advantages Disadvantages
globe
(unbalanced)
-large range
-good shutoff
-unbalanced forces
-high pressure loss
globe (balanced)
-high capacity
-large range
-balanced forces
-poor shutoff
-high pressure loss
ball
-high capacity
-tight shutoff
-moderate pressure drop applications
-tends to plug (except segmented ball)
butterfly
-high capacity
-low pressure loss
-slurry applications
-high torque
-large deadband
-affects flow through limited range (i.e. 0-
60%)
-tight shutoff requires special seat material
diaphragm
-slurry applications
-corrosion resistant
materials
-short diaphragm life
-limited pressure and temperature
-small range
gate -tight shutoff -used only with clean fluids