Why is it important to periodically turn the steam turbine in hot condition?
Steam turbine must be turned periodically while in hot condition to avoid serious troubles. In hot conditions, rotor of a turbine should not be permitted to remain in stationary condition longer than 3 minutes. The rotor will be bowed or distorted due to the resultant uneven cooling. Rolling with steam or turning with gear or by hand MUST be performed.
Hot conditions of turbines referred as:
- Gland /Sealing steam is left ON and vacuum condenser is operational.
- Leaking steam stop valves and Gland steam valves.
- Exhaust steam condenser /Vacuum condenser, condensate system operational.
- Drain line valves on common lines leaking can lead steam to heat the turbine.
- Turbine is not in rolling or rotating/turning by gear.
NOTE: Lubrication should be on at all times of rolling or turning operations.
