Our 134 MW steam turbine first stage pressure become low after outage. Its was running 126 kg/cm2 on maximum load which is now 115 kg/cm2. what happened & its remedy. Throttle pressure 160 kg/cm2.
>So, what have you done to investigate this matter?
To add to this, what is the power output of the steam turbine now? Are you taking the data at the same conditions (inlet steam temperature; inlet steam pressure; load; valve rack position)?
What is the valve rack position (actual, physical position measured at the valve rack) now versus what it was before for the same operating conditions (inlet steam temperature; inlet steam pressure; load)?
What was done during the outage? Were the control valves re-worked? Were the stop valves reworked?
Have you given consideration to the possibility that if the control valves and/or stop valves were re-worked that it wasn't done correctly? Or that if the control valves were re-worked and the position feedback device(s) (LVDT(s)) were not calibrated correctly?
Or, if the first stage turbine pressure transmitters were "calibrated" during the outage that the calibration was not done correctly?
And, again, what have you done to try to troubleshoot the problem--and, just as important: What were the results?