Some faults of Single seated control valve and their solutions

Some faults of Single seated control valve and their solutions

Partial faults of Single seated control valve and solutions:

Fault 1: the actuator does not act, but the power supply and signal lamp of the control module are on.

Fault 2: the actuator does not act, the power light is on and the signal light is not on.

Fault 3: actuator vibrates and sounds.

Fault 4: the actuator does not operate normally, but the motor does not stop after the limit switch acts.

Fault 5: the actuator belt is broken.

Fault 6: the actuator oscillates frequently due to improper adjustment of system parameters.

Fault 7: the actuator motor heats rapidly, vibrates and crawls, and stops acting in a short time.

Fault 8: the action of actuator is stepping and crawling, and the action is slow.

Fault 9: the actuator position feedback signal is too large or too small.

Fault 10: after the signal is added, the actuator is fully open or closed, and the limit switch does not stop.

1. Check whether the power supply voltage is correct; Whether the motor is disconnected; Whether the ten core plug is disconnected from the end to each wire terminal; Whether the plugs of motor, potentiometer and capacitor are in good condition; Judge whether the control module is in good condition by comparison and exchange method.

2. Check whether the polarity of input signal is correct; Judge whether the control module is in good condition by comparison and exchange method.

3. It is mainly because the sensitivity is adjusted too high, the insensitive area is too small and too sensitive, resulting in the instability of the small circuit of the actuator and oscillation. The sensitivity potentiometer is adjusted counterclockwise to reduce the sensitivity; The fluid pressure changes too much and the thrust of the actuator is insufficient; When the control valve is large, the valve often works at a small opening.

4. Check whether the limit switch and limit switch wiring are faulty; Replace the control module. 

5. Check whether the internal transmission part of the actuator is damaged or stuck; Whether the "zero position" and "stroke" potentiometers are adjusted correctly; Check whether the limit switch is correct.

6. Improper parameter setting of the regulator will cause varying degrees of oscillation of the system. For single loop regulation system, system oscillation may occur if the proportional band is too small, the integration time is too short, and the differential time and differential gain are too large. These parameters can be reasonably selected through the method of system tuning to keep the loop at a stable speed. 

7. Measure whether the input terminal of the control module is disturbed by AC 2V voltage; Check whether the signal line is isolated from the power line; Whether the potentiometer and potentiometer wiring are in good condition; Whether the feedback component operates normally.

8. Check whether the action time of the signal sent by the operator is correct.

9. Check whether the "zero" and "travel" potentiometers are adjusted correctly; Replace the control module. 

10. Check whether the function selection switch of the control module is in the correct position; Whether the "zero position" and "stroke" potentiometers are adjusted correctly; Replace the control module.