Prevent premature failure of mechanical-drive gas turbines

O. Y. Zidan, S. H. Alismail, A. AL-Shiha and M. Sabban, Saudi Aramco, Dhahran, Saudi Arabia A 24,000-hp gas turbine driving a natural gas compressor was started up for initial performance and overspeed tests, following an extended overhaul for major maintenance and upgrade to the entire train. The train was not suffering from any problematic issues, and so a normal overhaul maintenance was planned. During the initial test runs following the overhaul, the engine tripped on over-exhaust temperature and the unit failed to restart. A detailed inspection revealed significant damage to the No. 1 bearing rotor and casings. Additional downtime was required to replace the rotor and carry out repair