Siemens Energy presented various options to the client, including:
a) Complete replacement footprint turbine;
b) Repair of existing casing with new rotor and diaphragms;
c) New footprint casing and diaphragms while utilizing an existing spare rotor.
The customer decided to purchase option (c) – new footprint casing and diaphragms, which provided the greatest economy and minimal technical and schedule risk in replacing the original Delaval turbine. Additionally, design provisions were incorporated to improve moisture removal in the low-pressure section as well as improved control with the replacement of all valve gear operating parts and inlet trip throttle valve. All this led to efficiency and reliability gains.