Introduction

Pneumatic actuators are widely used in industrial automation control systems and are characterized by a simple structure, fast response and high safety. However, after long-term operation, various faults inevitably occur under the influence of air supply quality, environmental conditions and operating factors. Knowing how to judge and handle common problems helps you restore equipment operation quickly and ensure production continuity. This article breaks down the 6 common fault types of pneumatic actuators one by one into "cause + solution" and provides a quick reference for troubleshooting.

1. Fault 1: The Actuator Does Not Move

Possible causes

  • The air supply is not connected or the air pressure is insufficient

  • The solenoid valve does not operate or is damaged

  • The air circuit is blocked or leaking

  • Internal jamming of the actuator

Solutions

  • Check the air supply system to ensure normal supply and adequate pressure

  • Check whether the solenoid valve is energized and whether it reverses correctly; replace it if necessary

  • Check whether the air pipe connections leak or are blocked; clean or replace them

  • Dismantle and inspect the internal parts of the actuator, remove impurities and lubricate

2. Fault 2: Slow or Weak Action

Possible causes

  • Insufficient or strongly fluctuating air pressure

  • Faulty or blocked filter regulator

  • Worn internal seals causing leakage

  • Excessive load or mismatched selection

Solutions

  • Adjust the supply pressure to the design range to ensure a stable air supply

  • Clean or replace the filter regulator

  • Check the seals and replace the sealing rings if necessary

  • Verify the actuator selection to ensure the output torque or thrust meets the operating requirements

3. Fault 3: Action Does Not Reach Position

Possible causes

  • Improper stroke adjustment

  • The limit device is loose or shifted

  • Internal leakage in the cylinder

  • Abnormal control signal

Solutions

  • Readjust the stroke limit bolts

  • Tighten or calibrate the limit mechanism

  • Check the sealing performance of the cylinder; repair or replace it if necessary

  • Check whether the control system signal output is normal

4. Fault 4: Abnormal Noise or Vibration

Possible causes

  • Worn or loose internal parts

  • Excessive air flow impact

  • Loose installation

  • Insufficient lubrication

Solutions

  • Check the wear of internal components and replace damaged parts in time

  • Adjust the air supply pressure or add a buffering device

  • Check whether the mounting bracket and connection points are secure

  • Add lubricating oil or grease regularly

5. Fault 5: Air Leakage in the Pneumatic Actuator

Possible causes

  • Aged or damaged seals

  • Loose air pipe connections

  • Cracks in the valve body or cylinder

  • Poor sealing at the fittings

Solutions

  • Replace the sealing rings or seal assemblies

  • Tighten the air pipe fittings; replace the fittings if necessary

  • Check whether the housing is damaged; replace the equipment if there are cracks

  • Use sealant or sealing tape to improve sealing performance

6. Fault 6: Cannot Hold Position

Possible causes

  • Unstable air supply pressure

  • Internal leakage in the control valve

  • Degraded sealing performance of the actuator

Solutions

  • Stabilize the air supply pressure; add an air storage device if necessary

  • Check whether the control valve has internal leakage and repair it

  • Replace aged seals to improve air tightness

7. A Quick Fault Reference

Fault symptom Common causes Solution approach
No movement Air supply / solenoid valve / air circuit / jamming Check the air supply, replace the solenoid valve, clean the lines
Slow and weak Air pressure / filter regulator / seals / selection Stabilize the pressure, replace the filter regulator, verify the selection
Does not reach position Stroke / limit / internal leakage / signal Adjust the limit, check the cylinder, check the signal
Abnormal noise and vibration Wear / air flow impact / installation / lubrication Replace parts, add buffering, add lubrication
Air leakage Seals / fittings / cracks in the housing Replace seals, tighten, check the housing
Cannot hold position Unstable air pressure / internal leakage / seals Stabilize the pressure, check internal leakage, replace seals

8. Maintenance and Prevention Recommendations

To have fewer faults, do daily maintenance well:

  • Regularly drain water and impurities from the air supply

  • Keep the air supply clean and add filtration devices if necessary

  • Check the condition of seals and fasteners regularly

  • Establish equipment inspection and maintenance records

  • Operate in accordance with the instructions

Conclusion

The stable operation of a pneumatic actuator depends on standardized use and scientific maintenance. Timely troubleshooting and handling of common faults not only shortens downtime but also extends equipment service life. In practice, a maintenance plan should be developed according to the specific operating conditions to ensure long-term, efficient and safe operation of the system. For repair and technical support of pneumatic actuators, please feel free to contact our professional service team.

Zhejiang Huaershi Auto-control Instrument Valve Co., Ltd.

Since 1989 · 30+ years focused on pneumatic actuators and pneumatic valves

Website: www.hesvalve.com