Flow control valve, FO function
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FV3001 operates in FO mode; when this control valve loses air supply and power, theoretically the valve opening should increase, but the flow rate detected by the flow transmitter decreases. Since it is part of an important control loop, it’s impossible to determine whether the problem lies with the valve itself or with the actuator. Has anyone encountered this same issue or knows how to resolve it?
Gas opening is determined by the structure of the valve actuator, while electrical failures are determined by the structure of the positioner
FO stands for fail-open: when there is a problem with the air supply or the input signal, the valve remains in the fully open position. Please send the flowchart for analysis.
It is recommended to first understand the process. Perhaps this valve has failed and is open, but there might be other air-operated valves on the same pipeline that are closed, causing a decrease in flow rate Problems with the device must be analyzed and investigated from multiple perspectives.
The images usually only show the craftsmanship; it’s difficult for me to get them since I’m not on site
It is recommended to first understand the process. Perhaps this valve has failed and is open, but there might be other air-operated valves on the same pipeline that are closed, causing a decrease in flow rate Problems with the device must be analyzed and investigated from multiple perspectives. I think this is feasible
Thank you for your reply. I’m going to start working on resolving this issue now; the main problem is that the current conditions aren’t suitable to determine which part is causing the problem
Follow what 2L said: check the actuator and positioner to determine whether they are in a faulty operating state; if so, the issue is likely not related to the instrument
Is there a solenoid valve on the valve? Do you mean a power loss for the solenoid valve, or a loss of signal for the positioner? In the event of a loss of air supply, the valve should be able to reach the open position. However, if there is no solenoid valve on the valve and the signal from the positioner is also lost, then the positioners supplied by most manufacturers do not have built-in protection functions; as a result, the valve loses control. I’m not sure if it’s because there is no solenoid valve on the valve, nor are there any accessories with signal loss protection.