Why is there vibration in Rack&Pinion pneumatic actuators? What is the solution?

Rack&Pinion  pneumatic actuators  sometimes experience some malfunctions, such as Control Valve vibration. How should we solve these problems?  
Why does it vibrate? The main reason is that the selection of Pneumatic Actuator control valves does not meet the requirements of selection, such as unsuitable flow characteristics, large valve diameter, poor spring stiffness, etc., which causes vibration of the control valve; External vibration source, that is, the equipment pipeline itself has vibration; Vibration caused by fluid erosion.
How to solve it? If it is found that the vibration is inherent in the equipment pipeline itself, the equipment pipeline can be cleaned and readjusted to eliminate the vibration. If it is a problem with the Pneumatic Actuator control valve itself, a limiting orifice plate can be used to absorb some pressure drop, reduce throttling speed, overcome valve vibration, and the limiting orifice plate can also change the natural frequency of the system to avoid vibration caused by the natural frequency of the control valve being close to the natural frequency of the system.  
The above are the reasons and solutions for the vibration of Rack&Pinion  pneumatic actuators .