On the online replacement of intelligent positioners for control valves
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Currently, one of the steam main control valves has lost control suddenly. Since there is no bypass system, it was found that the Siemens positioner is damaged; it is planned to replace it. However, the adjustable range of this positioner is only 30%–50%. Since the self-diagnosis function of the Siemens positioner requires operation across the full range, an online replacement is desired. How can this be achieved? Additionally, Siemens smart positioners often experience sudden closures of the valves. Anyone with any experience or information regarding the debugging of Siemens smart positioners would be appreciated.
If you think Siemens is not good enough, you can take this opportunity to switch to positioners from other brands
It would be great if valve positioners had a function to export the calibration parameters; devices of the same model could then import and export these parameters, which would solve your current problem
The actuator is equipped with a handwheel, and those from Siemens can also be replaced online. For angular stroke valves, it’s simple: just find any angular stroke valve, calibrate it, and install it. For linear stroke valves, you need to find a similar valve, calibrate it as well, and then install it.
May I ask how to do it specifically? Could you share any relevant documentation?
The Siemens PS2 valve positioner can be replaced online, provided that a HART communication version is used; see the diagram for details. Our unit was previously replaced online as well; it didn’t have a bypass function and couldn’t be self-tuned. However, if there’s an opportunity to shut it down later, it will still be necessary to perform initialization in order to optimize the parameters of the locator.
We have encountered this issue before; the solution is to find a valve with the same operating parameters that can be used for calibration, calibrate the actuator using that valve, and then replace it on the faulty valve. However, this approach does not guarantee high precision – it’s only sufficient for temporary use as a workaround
Could you send me the Siemens information you mentioned above?