Control.com - Nerds in Control

Control valve is vibrated very much at its only opening and closing time.

Pump discharge press is about 20 kg/cm2.
* Pipe size : 14 inch
* Valve size : 8 inch
* max shutoff press(on V/V spec sheet) : 19 kg/cm2
* flowrate is sufficent

Vibrated so much that whole pipe line near to v/v trembled at this point.
Passed opening point, there is no vibration on v/v during its control.

Please write your valuable idea.

Have the valve flanges been overtightened?

Pete