Calibration Procedure : Control Valve

How to calibrate control valve?

Required Material:

1) Data sheet

2) Hart Communicator

Step wise Procedure: 

*Ask panel man to put the controller in manual mode for control loop 

*Isolate the Control valve from the process.

WARNING – The Isolation of control valve from the process shall be done by field operator. Careful step shall be done to ensure no upset to the operation.

*Hook up HART Communicator and verify some parameters by refer to data sheet such as Tag Number, OP and etc. 

*Change from normal mode to setup mode

*Select auto find stop (wait some minute)

*If full open is more than 100% select open adjustment and put new number as per calculation

*Make an auto calibration ( wait some minute)

*Verify the linearity by increasing and decreasing the travel (0%,25%,50%,75%,100%,75%,50%,25% and 0%of range)

*After completion of the job ask panel operator to put loops back in normal mode 

*Fill the calibration form and file it for future reference.

Example calculation

A: Max travel from stem   70mm

B: Scale plate   50mm

New open adjustment should be (50/70) X 100 = 71.48%