How to calibrate control valve?
You will need the following information:
Data sheet
You will need the following equipment:
Hart Communicator (Emerson 375 or 475 etc…)
What you need to
know to properly make the calibration:
Valves can be either air to open
or air to close. With one you start with the valve closed and the other with
the valve open. The procedure is the same for both types of valves.
Steps to calibrate
control valves:
1.
Ensure that the control valve is isolated from
the process if working on live system or newly installed system. “IMPORTANT USE LOCK OUT TAG OUT Procedures”
2.
Make sure the controller is in manual mode for
the control loop.
3. Verify steps 1 and 2 are done a
second time to insure safety of yourself and others that may not be involved in
the process being worked on.
4.
Hook up the Heart communicator and verify the
parameters by referencing data sheet with tag number of the instrument to be
calibrated.
5.
Change the control valve from normal to setup
mode.
6.
Select auto find stop (This should require 1 to
5 minutes depending on equipment used and being be calibrated.
7.
If control valve shows “Full Open more then 100%
- Select open adjustment and input new number that is associated with this per
data sheet and or per engineered calculation.
8.
Set an auto calculation (this should require one
to five minutes).
9.
Verify the linearity. This can be done by
increasing and decreasing the travel by quarter percentages (0%, 25% to 100%)
and (100%, 75% to 0%).
10.
To complete the process and verify that the controller
and the control valve are working properly put the loop back into normal mode
and test for correct calibration.
11.
Document all work having been done on standard
calibration form and properly log in system used and update any job books
required by company.
The information above is just one method and you should
follow the recommendations from the manufacture and your company
procedures if they are available.
You can find more information on Instrumentation here
ReplyDeletehttp://www.instrumentationtools.com/
Thanks
Bharadwaj
You can find more information on Instrumentation here
ReplyDeleteWebsite: www.InstrumentationTools.com here
Thanks,
Bharadwaj