Regarding the automatic initialization issue of Siemens valve positioners, I hope fellow users can offer some guidance.
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These past two days, with the guidance of forum members, I found a tutorial online on adjusting Siemens valve positioners. After reading it, I have the following questions, and I hope the forum members can offer some advice: When adjusting a Siemens valve positioner, one first manually selects the type of actuator, the rotation angle, and the stroke range of the valve stem – all of which are easy to understand. After that, the automatic initialization process begins. Automatic initialization consists of five items, as shown in the figure below. These items include: determining the forward and reverse actions, adjusting the zero point and stroke length, measuring the execution time (which is likely the stroke speed), minimizing the positioning increment, and optimizing the instantaneous response. What puzzles me now is how an intelligent locator can determine whether it should choose direct action or reverse action Shouldn’t this be set manually? There’s also the travel speed – how does the locator know what speed the user needs? Shouldn’t this be entered manually? Also, should the calibration of the valve positioner be done after the control valve is installed in the process pipeline or before installation? Personally, it’s better to make the adjustments before installation, as this allows one to see the movement path of the valve core and determine whether it can be closed tightly. I hope enthusiastic forum members can provide some guidance regarding the above questions. Thank you!
Automatic initialization includes five items that require no action, so there’s no need to get overly complicated about them. The Chinese translation of the instructions is also inaccurate. The positive and negative reactions he is referring to are those within the actuator itself, not those of the entire valve; you don’t need to worry about them. The forward and reverse actions of the entire valve need to be manually set separately. What can you do after seeing the movement trajectory of the valve core? Can’t one tell the movement trajectory of the valve core just by looking at it once it’s installed? Is yours a faulty valve? It must be installed first before making adjustments. Even if you adjust it before installing it, you still need to adjust it again after installation. Even if the installation location is changed, it needs to be adjusted again.
Hello, thank you for your reply! The reason I say it’s best to perform the adjustment before installing the valve is that once the control valve has been installed, it’s impossible to determine whether the valve core is in an open or closed state; that’s why I think so. Because during tuning, the valves before and after the control valve are definitely closed, so it’s impossible to see any process parameters; for example, if the valve stem moves downward, is the valve core actually closed or open? This is my concern.
For a valve, everything except the actuator is of mechanical design; when the valve stem moves downward, the valve core definitely closes~
It is related to the relationship between the valve core and the valve seat; it might also be open.
It is related to the relationship between the valve core and the valve seat; it might also be open.