If a control valve is hunting means means if we are giving
50% to the cv, the cv will open at 51% then slowly slwoly
it will reaches 49% , then it will reaches again 50%, this
type of action occured frequntly.. so what to do for solve
this problem. The possible cause is in volume booster or
positioner's relay.. positioner is double acting .. and
make siemens..sipart.The cv is double acting and mounted
for anti surge operation, it having 4 nos. volume booster,
one sov, one positioner, etc..?
Answers were Sorted based on User's Feedback
Check the following items:
1. Any loose connection or leakage of pneumatic signal.
Check all tube fittings with soap solution.
2.Check the gland packing should not be so tight. If feel
tight, get loose them a bit.
3. Check the pneumatic relays of Postioner. Get clean its
ports, nozzle, flapper etc.
4. Also check, that linkage, feed back mechanical link
should not have any dent, grove, burs etc.
aftabmazari@yahoo.com
Is This Answer Correct ? | 17 Yes | 0 No |
Answer / avinash d. pagar
Also please check volume booster function separately with
out positioner and then set factory setting of positioner.
again calibrate positioner by auto calibration. mostly
hunting and over shooting issues cause by booster error.
Is This Answer Correct ? | 4 Yes | 0 No |
what is control valve and how is work
7. What are tri-state devices and why they are essential in a bus oriented system
what is preventive maintenance , explain with difination
1 Answers Bapco Bahrain Petroleum Company,
I have a Control VAlve having size of 2 ".Only the known parameter is Pressure drop . Its 2 Kg. Then How to calculate control valve sizing means Cv.
What is the difference between intrinsic instruments and ATEX instruments?
what is cems analyzer explain with principle and drawing ?
In 2 wire transmitter 1 wire is used for power and other is used for signal( 4-20)ma In 4 wire transmitter 2 wires are used for power and 2 wires are used for signal (4-20)ma . but my question is "what is the criteria or parameters we have to consider while selecting these transmitters for eg( distance, safety zones etc.
How can we check Zero of DP type Level Transmitter onside?
Why not come out analog output in ABB EL3020 when display show correct value
difference between null and deflecting instrument.
While giving Power Supply of 24 VDC to a Transmitter,why Shield Terminal is connected either at Transmitter or at ISB.Why not Shield Terminal connected at both ends.If the Reason is to avoid Noise interference,which type of noice that is interfering.Is the Noice from the 24 VDC supply terminals or from any external source.
what is the difference between magnetic flow meter and mass flowmeter