Answer / k.thirunathan

calibration instrument required.
1.portable pneumatic calibrator
INPUT signal OUTPUT
Generate 0.2 kg/cm 0% of v/v travel
0.4 25%
0.6 50%

0.8 75%
1.0 100%

If you observe any deviation adjust accordingly.

Answer / deba

BY using DRUG calibrater we can easily calibrate just we
need a air line having pressure of 6kg as input of CV.
by giving 4-20mA signal through DRUG.
for example
4mA CV in close position
8mA 25%
12mA 50%
16mA 75%
20mA 100%

Answer / azmat

To calibrate a valve first check the input signal range if
it is 0.2 to 1.0 Kg/cm2 or different.
Calculate the span ( Difference between higher limit to
lower limit=1.0-0.2=.8 ) Now divide it in four equal parts
that is 0.2 Kg/cm2 this is 25% of the span.
Now check the valve travel like 2 inches, 3 inches or any
other value Divide it in four equal parts 25% of the travel.
Apply 25% of the span value+ 0.2= 0.4 Kg/cm2 it is 25% of
travel and apply full span value and see you get the
complete travel if you find difference adjust the spring
accordingly.

Answer / venkat

before do the stroke checking we have make sure the bench
calibration after that we should check 0-100% stroke

Answer / jayesh

If the valve is SMART now we can use a HART communicator to calibrate the control valve.Give the supply pressure according to the valve name plate then use HART communicator and give 0% 25% 50% 75% & 100% check the travelling of valve

Answer / shefeek salim

In Control valve Calibration,its of two types;
1.Stroke Calibration
2.I/P Converter Calibration
1.Stroke Calibration
it means for the movement (opening and Closing) measurement of stroke through the Scale,from 0 to 100 percentage of valve Closing/Opening,according to the standard air pressure supply or milli amps supply(3 to 15 psi,4 to 20 mA)
2.I/P Converter Calibrtion
It is comparatively simple one,but it can be done in two ways,
2.1 Simulate the std 4 to 20 mA as input Check the output from the I/P
2.2 Simulate the std 4 to 20 mA to the I/P converter as input and measure the Control valve stroke movement through the scale(0 to 100%)

Answer / c.grema@yahoo.com

first you have to now your limits if its pneumatic work
from 20 to 100kpa if current i 4 to 20ma
supply pressure,
1.bench set
2.beam alignments
3.calibration

in a electronic controller why we are using 250 ohm resistance in input signal?is i/p is necessary in control valve when we are using electronic controller give details?

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