Problems with the calibration of mechanical valve positioners
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Most of the valve positioners used in our company are intelligent valve positioners; mechanical valve positioners are also available, but we have not conducted any in-depth research on them. Which expert has experience with the detailed process of debugging mechanical valve positioners? How to adjust the 4~20mA signal for various adjustment positions of the valve at full open and full closed states?
Mechanical valve positioners have two threaded knobs: one is used to adjust the zero point, and the other is used to adjust the range. If it is necessary to change the adjustment mechanism, the feedback pedal needs to be replaced.
I learned it! ! ! ! ! ! ! ! ! ! ! !
Adjusting a mechanical positioner is much simpler than doing it intelligently! By understanding the direction of action, have the DCS send a 50% current signal; use the knob for adjusting the zero point to set the valve position at 50%. Then, have the DCS send a 25% signal, and use the knob for adjusting the range to set the valve position at 25% Typical mechanical positioners also have two screws that allow adjustment of the valve’s response time! Hope this helps!