1. Pneumatic Servo Valves
Manufactured in three basic types:
Pressure divider
Single-stage spool
Two-stage spool

3. Single- Stage Pressure Divider Type
Pneumatic Servo Valve
Used in low-flow applications (.5 CFM or less)

4. Single-Stage Spool Type
Pneumatic Servo Valve
Used in applications requiring up to 20 CFM
Torque Motor
Spool T P B A

5. Two Stage Spool Type Pneumatic Servo Valve
Used in applications requiring 20 CFM or higher

6. Pneumatic Proportional Valve

7. Pneumatic Proportional Valve

8. Single Stage Proportional Valve

9. LVDT
Converts the spool position into a proportional electrical signal

10. Electro-Pneumatic Regulator

11. Pneumatic Linear Positioner

12. Valve Amplifier

13. Computer Control

14. Troubleshooting and Adjusting the System
Nulling the Servo Valve

15. Troubleshooting and Adjusting the System
Is the problem electrical or pneumatic?
Attempt to operate the valve with a test box
If the actuator moves normally when driven with the test box,
the problem is likely electrical

16. Check the feedback signal from the transducer with an oscilloscope
Troubleshooting and Adjusting the System
Check the feedback signal from the transducer with an oscilloscope
or test box.
An erratic output signal normally indicates a bad transducer
The cable between the transducer and controller should also be checked