Reconditioning of hot gas turbine parts is driven mainly by lifetime and performance requirements. Commonly, the first approach in reconditioning is to achieve an exact reproduction of a new manufactured part, by following new part specifications. However, this may prove to be too costly and unnecessary. The unique OEM experience, allows ALSTOM to widen these specifications in order to optimize repair costs, improve throughput time and possibly reduce parts scrap rate without sacrificing lifetime and performance. This post-development is based on MI calculations re-calibrated and reinsured by extensive empirical field feedback and performance statistics over the whole GT fleet with millions of operating hours. This paper presents an overview of the required area of the OEM’s expertise and field data within post development, substantiated by examples from daily operations. The work is performed in order to ensure safe remaining part lifetime along with full functionality and known performance impact. Parameters influencing the remaining part lifetime are micro-structural degradation, crack allowances, coating properties and minimum wall thicknesses, while, parameters influencing performance are airflow specifications, radial clearances, sealing design and surface roughness. Furthermore, different manufacturing techniques and new technologies get investigated and then implemented whenever there is an opportunity to optimize process cost effectiveness and reach higher quality standards. This is done in order to ensure that the company retains its competitive edge over other reconditioning companies. As the complexity of components varies, the unique knowledge of each component allows ALSTOM to develop the most favorable reconditioning processes. This enables state-of-the-art reconditioning and repair methods to be utilized. Thus ensuring optimum throughput time, while minimizing scrap rates and maintaining performance and lifetime requirements. This unique experience and knowledge from the reconditioning processes is transferred as a benefit to the customer and also utilized in future designs, resulting in improved new part designs and optimized life cycle costs.

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