Pneumatic actuators hold an important position in industrial production, but they mostly work in harsh environments such as high temperature, high pressure and strong corrosion, so the failure rate is relatively high. Besides common faults such as the valve body not moving, failing to close to the zero position, no feedback signal and unstable signal pressure, there are also some "special faults" — for example, control valve vibration. This article specifically analyzes the causes of control valve vibration and the handling measures.
1. What Is Control Valve Vibration
Control valve vibration is a special fault of pneumatic actuators. Once it occurs, it will cause the control system to fail to work normally. It is often not caused by a single reason and needs to be checked item by item.
2. Three Main Causes of Vibration
1. External vibration sources
The equipment pipeline itself vibrates, "transmitting" the vibration to the control valve.
2. Selection not meeting requirements
Improper control valve selection, such as unsuitable flow characteristics, an oversized valve bore or poor spring stiffness, causes vibration.
3. Fluid erosion
Vibration is produced by fluid erosion.
3. Targeted Handling Measures
For vibration of the pipeline itself
Clean and readjust the equipment pipeline so that its vibration disappears.
For problems of the control valve itself
Use a restriction orifice to solve the problem:
-
A restriction orifice can absorb part of the pressure drop, reducing the throttling speed and overcoming valve vibration
-
A restriction orifice can also change the system's natural frequency, avoiding resonance caused when the control valve's natural frequency is close to the system's natural frequency
Key move: a restriction orifice both reduces pressure and speed and shifts the natural frequency; it is a common means of treating "valve vibration."
4. Vibration Troubleshooting Quick Reference
| Vibration cause | Judgment | Measure |
|---|---|---|
| External vibration source | The pipeline itself vibrates | Clean and readjust the pipeline |
| Improper selection | Flow characteristics / bore / spring stiffness do not match | Reselect the model |
| Fluid erosion | Vibration caused by medium scouring | Restriction orifice to reduce pressure and speed |
| Resonance | Natural frequencies are close | Restriction orifice to change the natural frequency |
Conclusion
Although control valve vibration is a "special fault," as long as you troubleshoot in the order of "external vibration source → selection → fluid erosion," the root cause can mostly be found. In particular, the restriction orifice is a very practical means, as it both reduces pressure and speed and shifts the natural frequency. For technical support in troubleshooting pneumatic actuator control valve vibration, 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: