After a recent major outage, our steam turbine is experiencing higher-than-normal vibration at specific load conditions. The vibrations are not present at lower loads but increase significantly as we approach full load.
Here’s what we’ve checked:
Rotor alignment was verified during the outage.
Bearing temperatures are within spec.
Lubrication system is functioning properly.
Has anyone encountered similar post-outage vibration issues? Could this be related to blade tip clearance or steam flow path changes?
We had a similar issue, and it turned out to be steam path erosion affecting the last-stage blades. Check your flow path for any signs of erosion or deposition.
Look into your bearing clearances. Sometimes, thermal expansion post-outage can change clearances, leading to vibration. We had to adjust our bearing pads to fix the issue.
Ensure your balancing weights were properly adjusted after the outage. We’ve seen cases where incorrect weight distribution caused vibration issues at higher loads.