During major overhaul and upgrade of Combined Cycle Unit5, a large number of bolts on the stationary diaphragms of the intermediate pressure lower casing and the upper casing of the steam turbine could not be removed and drilling was the only solution.
A team of our technicians was mobilized and along with portable drilling machines they started drilling out the broken-stuck bolts on the lower casing. At the same time all diaphragms were transferred to our premises together with the upper casing to proceed with drilling on our CNC machines, for saving time.
The upper casing was machined on our heavy duty CNC boring machine and the stationary diaphragms on our CNC milling centers.