Control valves
Upcoming SlideShare
Loading in...5
×

Like this? Share it with your network

Share

Control valves

  • 876 views
Uploaded on

basic understanding of control valves ...

basic understanding of control valves
working principle of control valves
flow characteristics of control valves

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
No Downloads

Views

Total Views
876
On Slideshare
875
From Embeds
1
Number of Embeds
1

Actions

Shares
Downloads
88
Comments
0
Likes
1

Embeds 1

http://www.slideee.com 1

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide
  • The actuator accepts a signal from the control system and, in response, moves the valve to a fully-open or fully-closed position, or a more open or a more closed position (depending on whether 'on / off' or 'continuous' control action is used).

Transcript

  • 1. 1 Presented by: Syed Waqas Haider Process Engineer
  • 2. Control Valves control conditions (flow, pressure, temperature, and liquid level ) open or close in response to signals received from controllers Controller compare a "setpoint" to a "process variable" (value provided by sensors) 2
  • 3. 3 Control Valves Rotary Motion Butterfly valves Ball vales Plug valves Linear Motion Globe Valves
  • 4. Three main parts Valve's actuator Valve's positioner Valve's body 4
  • 5. The purpose of the valve actuator is to accurately locate the valve plug in a position dictated by the control signal 5
  • 6. Pneumatic Valve Actuators: Adjust the position of the valve by converting air pressure into rotary motion or linear motion. Piston and Diaphragm Actuators are examples of Pneumatic Actuators Electric Valve Actuators: An electric actuator is powered by motor that converts electrical energy to mechanical torque Hydraulic actuator: Consists of a cylinder or fluid motor that uses hydraulic power to facilitate mechanical operation. The mechanical motion gives an output in terms of linear, rotary or oscillatory motion 6 according to their supply
  • 7. Multi-turn actuator gives torque for at least one full revolution Part-turn actuator gives torque for less than one full revolution Linear actuator opens and closes valves that can be operated via linear force--sometimes called rising stem valves 7 according to their movement
  • 8. Positioners are instruments that help improve control by accurately positioning a control valve actuator in response to a control signal Positioners receive an input signal either pneumatically or electronically and provide output power to an actuator 8
  • 9. Some of the mechanisms i. Force Balance Positioners ii. Motion balance Positioners iii. Electronic Positioners 9
  • 10. 10
  • 11. 11
  • 12. 12 Sensor to detect valve position Micro-Processor Error = Position - Signal
  • 13. Valve Bodies 13
  • 14. 14 Quick Opening: Quick open plugs are used for on-off applications designed to produce maximum flow quickly Linear: produces equal changes in flow per unit of valve stroke regardless of plug position, used where valve pressure drop is a major portion of the total system pressure drop Equal Percentage: change in flow per unit of valve stroke is directly proportional to the flow occurring just before the change is made, generally used for pressure control