Problems with mechanical valve positioners?
Thread Content
The valve does not operate from 0 to 20, and it starts to function only above 25. What’s going on? ?
The quality of an electrical conversion gas is determined by its linearity; in your case, the linearity is clearly poor, which is usually caused by aging or misalignment of the mechanical structure. It is recommended that you recheck the zero point and range several times
What was said upstairs is correct; it is recommended to re-verify the zero range and linearity.
Try zeroing and setting it to full scale; if that doesn’t work, try a different amplifier. If that still doesn’t work, try a different coil
. . . Mechanical ones can fail at any stage; it’s either 0~X or X~100 – old-fashioned, I guess. . . Take the chance to switch to a smart one!
Adjust the zero point according to the output pressure! Don’t turn it up too much.
Mechanical types do indeed experience similar problems; due to variations in air supply pressure, the zero point may shift. It is recommended to adjust the zero point and range; unless the turbine remains unchanged no matter how it is adjusted, it should be possible to get them set correctly. Try several times; it’s okay if it gets damaged – just be brave enough to give it a try~!
Mechanical aging – sometimes, it’s difficult to perform proper zeroing, which indicates that the aging is too severe; in such cases, the parts can be replaced.
First, zero the gauge. If the zero reading is correct, it is recommended to check whether the diaphragm of the pneumatic valve has aged and is leaking air. When the opening is small, the air pressure is low; air leakage prevents the valve from operating.