1. What caused the 2007 Indian power plant boiler tube rupture?
Investigation revealed long-term overheating due to flame impingement. Tubes showed significant wall thinning and creep damage. Inadequate water treatment led to internal deposits. Lack of regular thickness measurements missed warning signs. Resulted in 3-month outage and $12M in repairs.
2. How did flow-accelerated corrosion cause a US plant failure?
Single-phase FAC thinned economizer tubes by 60% over 5 years. Improper pH control accelerated carbon steel dissolution. Failure occurred during a load change when stresses peaked. Now requires annual UT surveys of susceptible areas. Led to industry-wide FAC program updates.
3. What lessons came from the European superheater cracking incident?
Thermal fatigue from frequent startups cracked alloy tubes. Inadequate support design allowed excessive vibration. Post-failure analysis showed improper heat treatment. Now requires finite element analysis for new designs. Changed operating procedures to limit thermal cycling.
4. How did coal quality change cause widespread tube failures?
Switch to high-sulfur coal increased fireside corrosion rates. Unexpected chlorine content caused accelerated wastage. Tubes lasted only 18 months instead of 5 years. Forced conversion to corrosion-resistant materials. Now require fuel analysis before any changes.
5. What systemic issues led to multiple tube failures in an aging plant?
Deferred maintenance allowed multiple damage mechanisms to progress. Lack of documentation made remaining life assessment difficult. Outdated inspection techniques missed developing flaws. Resulted in complete boiler retubing and management overhaul.
