Interested to Buy Any Domain ? << Click Here >> for more details...
Answer Posted / aftab ahmed mazari
Following procedure should be done for control valve
calibration.
Suppose it is spring loaded and direct action.(Direct
action means at top of diapgargm signal and with the
increase of signal, stem will move downwards or the stem
will extend).Also valve is signal to close. Check its Bench
Set. Suppose it is 6 to 21 PSI.
1. Set pressure regulator of positioner at about 30 PSI.
2. Apply 3 PSI (4 mA if positioner is smart or electronics)
signal to Positioner.Gradullay increase signal. Note the
movement of stem.
3. Apply 6 (8 mA),9 PSI (12 mA), 12 PSI (16 mA) and 15 PSI
(20 mA) signal. Valve stem should move accordingly and
indicator must show 25%,50%,75% and 100%.
4. If error, remove it from zero and span of positioner.
5. If facing any error problem, give signal 50% and then
remove error. Rest will be ok automatically.
6. Suppose valve is normally closed and at any vent service
and signal to close as I mentioned earlier, then make shut
close of valve at 14.5, or 14.7 PSI. Valve may start
closing at 2.75PSI.
7. If valve is at control operation, like level, pressure
etc, then calibrate it accurately.No need to calibrate it
at 2.75 and 14.5 PSI.
aftabmazari@yahoo.com
| Is This Answer Correct ? | 31 Yes | 3 No |
Post New Answer View All Answers
How to Calibrate Radar Level Transmitter in Field
how does we calibrate a square root flow transmitter ,give an example and explain it step by step like range calculation , calibration hook up series connection , zero check , and how to apply pressure , and if not geting proportional output then what should we do ?
in mass flow meter what is drive friquancy ?
how u choose thermowell lenght n pnumatic C/v size?
what is temperature compensation?
Describe the function of Accumulator into the Pump
Why humidity limit is 30 to 55 % for raw material storage?
what is stroke check for field instument transmetter's & AOV's
what is the procedure to callibrate temp controller ,pressure controller,etc. suppose a temp controller showing error 1.5 degree centigrate how can i minimize it.
How to Calibrate Flammable gas detector in field
Sir , i have completed my M.Sc In Instrumentation and presently working in Maintenance department 3 yrs Exp , is there is any possible for work in offshore ..
how to calibrate Necleuonic level transmitter.?
What is the exact differences between HART,FOUNDATION FIELDBUS,PROFIBUS?
What is the function of solenoid valve in on/off & shutdown valve and why it is not used in control valve normally?
Can anyone convert a 5/2 way or 3/2 way valve into an ISO valve?
