how to calibrate motorized operated valve?
Answer / subash krishnan
Instruments required:
Multimeter, potentiometer, point position trnasmitter (PPT), Valve Positioner, allen keys 3mm and 4 mm , double-end spanner (12-13), mini screw driver.
1.Initially check the motor-operated valve for open/close manually since the torque set should be accurate inorder for accurate calibration process.
2. Choose a potentiometer a desired based on the number of rounds in which the valve opens or closes. For example if the rounds are maximum choose a potentiometer which has the lowest resitance (1 kilo ohm).
3. Also choose the matching teeth wheel for the chosen potentiometer.
4. Take a point position transmitter (PPT) which is used to give the present position of the motor-operated valve. The PPT is of two different ranges based on resistance (0 to 230 ohms) & (0 to 500 ohms)
5. For every motor-operated valve the close position resistance is set as 100 ohms and the open position is set as 230 (to 500 ohms).
6. The point position transmitter is now given the power supply of 24V DC .
7. Now the resitance for the close position i.e. 100 ohms is given as input and the current should be tuned as 4mA.
8. Now the resitance for the open position i.e. 230 to 500 ohms is given as input and the current should be tuned as 20mA.
9. The steps 7 & 8 are repeated until the PPT gets set to 4 to 20mA.
10.Now the teeth wheel is matched with the matching wheel in the motor-operated valve setup so that the resistance could change in accordance with the valve's open/close operation.
11. The valve is now checked for open/close so that the current for open/close should be in the range of 4-20mA.
12. Now the positoner unit should checked whether it displays 0-100% for the open/close position. Otherwise the positioner display should be tuned for 0-100%
13. There is an actuator tuning adjustment in the positioner unit inorder to do fine calibration for zero and span if there are any minor errors in open/close position.
Is This Answer Correct ? | 10 Yes | 0 No |
how to calculate orifice sizing? and tell me if pipe size bet 50mm t0 200mm then we can use pipe flange??? and above 250mm pipe size should i use D & D/2 Flange? is it right or wrong?
A flange is used for instrument connection for a system with a design temperature of 316C (600F) and a design pressure of 1000 kPa (145 psi). What is the class rating of the flange to be used for this application? Explain your answer
how to measure oxygen which methods are using?
open tank and close tank leavel transmiter about range and calibration
Hi, I'd like to know the purpose of MOS (maintenance override switch). At site, these switches are installed in a stanchion with the transmitter (connected to ESD). thank you.
3 Answers Adani, Adani Wilmar,
what is the PID controller?
Can SmartPlant Instrumentation be used in a concurrent engineering environment?
what is absolute pressure, gauge pressure and atmospheric pressure?
Regarding , there is an air cooler which control the fans(50% of AV FANS) by temperature in outlet , and the louver of Air cooler is controlled by HIC from control system , So if on Air cooler we will consider 2 individual I/P converter or positioner?
0 Answers Chagalesh Consulting Engineers,
Area classification, Equipments, Gas groups, temperature classification, Ingress protection, Fire Extinguishers.
what is control valve and how is work
canu tell me why 4-20 ma and why not this 3-25ma?please give reason of this value.