How long does it take to warm up a steam turbine?

• A. 5-10 minutes
• B. 10-15 minutes
• C. 15-25 minutes
• D. 30-45 minutes

Answer: (B)

Warming up a steam turbine properly is about preventing thermal shock and ensuring all moving parts and lubrication reach the right temperatures before loading the turbine. When a cold turbine starts, metal components and bearings expand at different rates, and oil viscosity is not yet appropriate, which can cause excessive wear or damage. A controlled warm-up of about 10 to 15 minutes allows steam and feedwater temperatures to rise gradually, lubricating oil to reach the correct viscosity, and bearing housings to come up to operating temperature. This timeframe provides a practical balance between protecting the equipment and minimizing downtime, though adjustments may be needed for larger, heavier units or longer piping.