Fluctuations in the output of the paid assistance locator

Thread Content

The several lines in the graph represent the oxygen flow rate controlled by the control valve, which is maintained at around 5000 Nm³/h; among them, the purple line shows significant fluctuations, with a maximum variation of around 600 Nm³/h. When the control valve is set to automatic mode, fluctuations occur; when it is switched to manual control, slight fluctuations in the valve stem can also be felt on site. Previously, the safety gates and command channels responsible for sending output commands were replaced, but that did not solve the problem; it was necessary to replace the valve positioners entirely. Once replaced, everything worked normally. However, some of these positioners started to exhibit problems again after just a few months, while those of better quality could function properly for up to a year. Sometimes, several devices would start having issues one after another over time. I also tried replacing the filter pressure regulator, with no improvement. The valve positioner is a Fisher DVC6010; I’m seeking advice on effective solutions, preferably one that can resolve the issue right away!