# Different types of Control valve calibration:

**URL:** <https://forumautomation.com/t/different-types-of-control-valve-calibration/7425>\
**Category:** Calibration\
**Created:** [November 15, 2019, 7:04pm UTC](https://forumautomation.com/t/different-types-of-control-valve-calibration/7425 "2019-11-15T19:04:23Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![sivaranjith](https://forumautomation.com/letter_avatar_proxy/v4/letter/s/ba9def/32.png) [@sivaranjith](https://forumautomation.com/u/sivaranjith)\
**Post date:** [November 15, 2019, 7:04pm UTC](https://forumautomation.com/t/different-types-of-control-valve-calibration/7425/1 "2019-11-15T19:04:23Z")

</div>

![control%20valve%20fire](https://cdn.forumautomation.com/original/2X/e/e79ca669457841581fbf7a2469b0760cd708df58.png)

[**Control valves**](https://forumautomation.com/t/what-is-control-valve-purpose-of-a-control-valve-in-a-process-loop/4348) are essential components of process industry thus it make really important to calibrate control valve periodically. There are importantly two ways to calibrate a control valve.

- Stroke Calibration
- I/P convertor calibration

[color=#ff0000][size=5]Stroke Calibration:[/size][/color]

[**Stroke calibration**](https://automationforum.co/control-valve-stroke-checking/) approach demonstrates that the actuator has sufficient force to open and close the valve. Calibration is required when the valve and actuator are first installed to decide the stroke positions 0 and 1 in the valve. Measurement of the stroke position of the [**valve actuator**](https://forumautomation.com/t/what-are-the-types-of-valve-actuators/2470) from 0 to 100% of the valve closure / opening.

### Procedure:

- Connect the control valve and its accessories according to the connection

- Attach air pressure machine to the regulator

- Regulator change to demand as per data sheet of POSITIONER output pressure.

- Set Loop Calibrator to provide POSITIONER with the latest output signal (4-20mA).

- Apply 4 mA to positioner using loop Calibrator

- Test the stem motion if there is a mistake in the positioner to change the null calibration screw.

- Apply 20 mA

- Test the position of the head, if there is any defect, the span screw in the positioner must be changed.

- Apply 0%,25%,50%,75%,100% of the signal & observe the corresponding stroke of the valve & stem position.

[color=#ff0000][size=5]I/P converter calibration of valve:[/size][/color]

[**I/P converter calibration**](https://forumautomation.com/t/i-p-converter-calibration/5994) is comparatively simple process, but it can be done in two ways: Simulate standard 4 to 20 mA as input check output from I / P. Or Simulate std 4 to 20 mA as input and measure the movement of the control valve stroke through the scale (0 to 100%).

### Procedure:

- Remove from the housing the final assembly module.

- Place the range jumper in the high range Hi position

- Link air supply via the air supply regulator to the output port.

- Connect an accurate output indicator to the output signal port.

- Make sure that an output meter port or threaded connector is mounted. For units shipped without output gages, a threaded plug is given.

- Apply a 4.0 mA (Vm = 1.0 V) signal and adjust the zero screw to 3.0 psi output. The output increases in the direction of the clockwise direction with zero screw rotation.

- To check and complete the calibration, repeat the last two moves.