Integrity Inspection of a Steam Turbine Rotor in a Geothermal Power Plant

DOI

10.2991/eame-15.2015.137How to use a DOI?

Keywords

rotor shaft; integrity inspection; non-destructive test; defects

Abstract

A 55 MW steam turbine in geothermal generation power plant has been in service for 26 years. This turbine stopped working in 2013 due to the failure of a first stage blade. By considering the damage and maintenance works are important for geothermal turbine to maintain the reliable operation before it will be back in use, the integrity inspection must be conducted. The methodology for integrity inspection was nondestructive tests e.g.; visual inspection, dye penetrant, UT phased array, eddy current, hardness, chemical composition test and microstructure analysis using replica technique. Chemical composition analysis, hardness data and microstructure analysis gave evidence that the material rotor met the standard of ASTM A470 class 8.Visual inspection and dye penetrant found that there were some surface defects and microstructure analysis on replica showed that pitting was observed. However, UT phased array and radiograph results revealed that no internal defects were found, which indicated that the surface defects only occurred on the surface and pitting did not propagate. Results of eddy current inspection proved there were no fine cracks on all areas. From the inspection results, it can be summarized that at the present, the steam turbine rotor is in good condition and safely returned to service after minor repair.

Copyright

© 2015, the Authors. Published by Atlantis Press.

Open Access

This is an open access article distributed under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).

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TY  - CONF
AU  - M. Nurbanasari
PY  - 2015/07
DA  - 2015/07
TI  - Integrity Inspection of a Steam Turbine Rotor in a Geothermal Power Plant
BT  - Proceedings of the 2015 International Conference on Electrical, Automation and Mechanical Engineering
PB  - Atlantis Press
SP  - 483
EP  - 485
SN  - 2352-5401
UR  - https://doi.org/10.2991/eame-15.2015.137
DO  - 10.2991/eame-15.2015.137
ID  - Nurbanasari2015/07
ER  -