Friday, July 3, 2009
Interview Question: How to Calibrate Control Valve? Which Instrument is Used?
For the calibration of a control valve a loop calibrator or a pressure calibrator can be used between 3-15psi.Check the valve position for 3psi which is to be 0 for a NC type valves.In such manner check the valve position for various ranges(6psi,9psi,12psi & 15psi).the valve position should be 0 for 3psi and 50% for 9 psi and completely opened for15psi.
The same procedure is applicable for NO type valves.The valve is open for 3 psi and completely closed for 15psi.Any errors occurred may be rectified by Zero span adjustment.