The Yamaki positioner switch controls oscillations of less than 20% up and down
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The Yamaki positioner switches cause fluctuations of less than 20%, with oscillations up and down; after adjusting the sensitivity, the problem reoccurs the next day. When the fluctuation is above 20%, everything remains stable, but once it drops below 20%, oscillations occur again, resulting in large fluctuations in flow rate. The issue persists even after replacing it with a new Yamaki unit. I seek expert assistance – all 5 control valves are experiencing this problem.
What medium is being measured? Medium temperature, pressure – what type of control valve? Is the fault status FC or FO? How long will this valve last approximately?
1. It is recommended to check the actual flow rate when the valve is opened to less than 20% of its full opening, and compare it with the flow rate values specified in the valve’s data sheet, to determine whether the flow rate is too low. 2. Check again the flow characteristic settings of the Yamaki positioner.
It's a chlorine detector; the medium temperature is 20 degrees. It’s a sleeve valve, and its status is FC (faulty). The valve has been in use for 8 years, and a new locator has been installed, but the problem persists
I had been using Yamawa before; it worked fine for 7 or 8 years. This issue only started appearing recently, so I didn’t consider the possibility of too low flow rate being the cause. I don’t understand these traffic characteristics, bro. How do I figure it out?
The spring stiffness of the actuator for the control valve may be insufficient; considering a replacement.
Did the process switch to automatic mode when surging occurred? Try running the process in manual mode to see if it can be stabilized. If it can be stabilized, then there should be no problem with the positioner; adjust the PID parameters and switch to automatic mode before trying again. If that still doesn’t work, switch to the bypass valve and check the cylinder
It’s acting up~~~; when it does that, ding_ding_ding, checking nothing helps at all............
Does it wheeze when in use, or does it wheeze even when turned off?
I suspect it’s a problem with the valve core structure; I’ll talk to the manufacturer and have the valve core structure replaced. In my previous case, switching from a single-seat design to a sleeve design resolved the issue
Forget those posts about digging up graves from a few years ago; just give your guesses or conclusions directly. I think it’s because the demand downstream is too low, or the flow rate inside the pipeline is insufficient, so the control valve isn’t operating under normal conditions. Sleeve valves are generally used for noise reduction; that is, when there is a large pressure difference between the inlet and outlet, as in the case of steam or hot water. If there is fluctuation at low opening degrees, it is usually a pressure control valve. Add some hysteresis at 20%, and if that doesn’t work, add some hysteresis in the upper-level program.