Reasons for Vibration of Pneumatic Control Valves and Its Treatment
Introduction
The pneumatic control valve is an indispensable control component in the automatic control system of modern industrial production. Its failure will inevitably affect the normal operation of the entire system, so the problem of pneumatic control valve vibration needs to be solved in time to ensure the stable operation of the system.
Reasons for Vibration of Pneumatic Control Valves
Based on experience, pneumatic control valve vibration is generally caused by the following factors:
1) The hole of the valve body is not located in the middle of the flow path. The force generated by the pressure difference in the valve body can cause the valve core to vibrate, resulting in an increase in vibration.
2) The size of the valve hole is not suitable. When there is a large resistance between the seat and the valve stem, or the size of the valve hole is not suitable, the valve stem will be blocked and cause the valve vibration.
3) The valve stem sealing ring is too old or not installed correctly. If the sealing ring is too old or not correctly installed, air leakage occurs between the valve stem and the valve seat, the valve stem is subjected to dynamic load due to the pressure difference, and the vibration increases.
4) Media temperature is too high. When the media temperature is too high, the viscosity of the medium is too low, which will lead to an unstable flow rate, resulting in an increase in vibration.
5) The valve stem is not parallel to the valve seat. This causes the seal between the valve stem and the valve seat to become unstable, which in turn causes the vibration of the valve core to increase.
6) Improper installation of fluid lines and dampers. When the fluid lines are installed too tight or not at the same level, or the dampers are not installed properly, this will cause the vibration of the pneumatic control valve to increase.
7) Excessive fluctuation of the pressure of the system can cause the valve to vibrate continuously.
Treatment of Pneumatic Control Valve Vibration
The following measures can be taken to reduce the vibration of a pneumatic control valve.
1) Adjust the central position of the valve hole by changing the inlet and outlet piping, changing the length of the valve stem, or changing the position of the valve seat to reduce vibration.
2) Increase the flow area of the valve to reduce resistance and reduce vibration.
3) Replace the sealing ring and gasket, and adjust the gap of the valve rod.
4) Install a throttle and a damping device to reduce vibration.
5) Increase the stiffness of the support when installing the valve, or using a flexible tube connection to reduce valve vibration.
6) Increase the media temperature to ensure a stable flow rate and reduce the vibration of the valve.
7) The valve stem should be parallel to the valve seat to avoid leakage of the media and reduce valve vibration.
8) Adjust the pressure of the system.
Conclusion
This article has discussed the reasons for vibration of pneumatic control valves and the methods for treating the vibration. By following the tips in this article, we can effectively reduce the vibration of the pneumatic control valve and ensure the stability of the control system.
