Stock Checking in control Valve

Stock Checking in control Valve/ Strock Checking Procedure

Equipment and Materials Required:-

1. Air Instrument.
2. Loop Calibrator (4 – 20 mA).
3. Connector.
4. Tubing and ferrule sets.

Procedure for Control Valve Stroke checking:-

1. Connect the control valve and its accessories as per the connection diagram (consider the control valve is air to close‘ valve).
2. Apply Air Instrument for Supply pressure to Regulator.
3. Adjust the Regulator until pressure as per datasheet for Supply Pressure to POSITIONER.
4. Set Loop Calibrator to provide current Input Signal (4-20mA) to POSITIONER.
5. Apply 4 mA to positioner using loop Calibrator.
6. Check the stem movement it must be at the minimum position if there is any error adjust the zero calibrating screw-in the positioner.
7. Apply 20 mA to positioner using loop Calibrator.
8. Check the stem position it must be at 100% position if there is any error adjust the span screw in the positioner
9. Apply 0%, 25%, 50%, 75%, and 100% of the signal & observe the corresponding stroke of the valve & stem position.