What is the cause of valve stem vibration in electric single seat control valves?
3, liquid medium through the valve, resulting in cavitation caused by shocks, higher frequency, usually accompanied by valve howling. High temperature large pressure difference, the use of single seat valve is relatively easy to happen, this is the control valve (valve body structure) type selection caused by improper,4, the valve core resonant frequency and pipe and fluid frequency consistent with the vibration caused by higher frequency, usually accompanied by pipe vibration. Change the valve at both ends of the process, valve opening may be eliminated.
2, the valve and the regulated object response time caused by shock, difference between this phenomenon and a control valve input signal is stable or volatility is less than the corresponding adjustment of the valve stroke. Common in the pneumatic valve with valve positioner, electric valve may also occur. Increased valve actuator damping can be eliminated.
Single seat control valve stem vibration causes are many, there are common:1, the response time of the regulating system coincides with the response time of the regulated object, resulting in system shock, when the shock frequency is low, and the input signal of the control valve is also synchronous shock. The magnification of the system, such as the parameters adjusted by PID, can be removed by changing the parameters.Coincidence response time
