Fluctuations in the control valve of the Siemens positioner
Thread Content
There is a control valve in the unit that uses Siemens positioners; it is a gas-shut off valve. Recently, fluctuations in its output have occurred. The operating pressure is 300 kPa, and the process pressure is generally adjusted within a narrow range of 50 to 60 kPa. An inspection at the site revealed air leakage in the input gas supply, and after tightening the connections, the leakage stopped. The situation improved significantly after automatic calibration, but fluctuations still occurred. The valve core was inspected and found to be in good condition; there was slight wear on the valve stem, but polishing it and applying lubricant resolved that issue as well. Additionally, the output from the pressure regulator fluctuates and is unstable, and this problem persists even when the pressure is set to 350 kPa. I’m not sure if this is related to the other issues. I hope experts can help me figure this out.
Check whether the cylinder is leaking; there is a suspicion that there is a leak somewhere in the gas circuit. Or the positioner piezoelectric valve is damaged.
The air circuit has been checked; there seems to be no leaks. The cylinder hasn’t been checked yet. How can one determine if a piezoelectric valve is damaged?
There is indeed doubt about this, but it’s troublesome to operate the valve manually and testing cannot be done at any time; therefore, I want to replace the pressure relief valve.
The simplest way to determine this is by replacing it with a new locator or piezoelectric valve module.
Mm-hmm, if the fluctuations continue, I’ll need to consider replacing it. Thanks for the reminder. :)
““The output of the pressure regulator fluctuates” may be due to an unstable pressure regulator, which causes fluctuations in the air supply; try replacing it with another one......
Well, I’m considering a replacement, thank you!