Title: Pressure Part Failures in Vintage Boilers
1Pressure Part Failures in Vintage Boilers
2As our power stations increase in age, so does
the frequency and mechanisms of pressure part
failures.
3Three Commonly Occurring Failures in Older Power
Plants Include
- Fatigue Related Failures
- Overheating Related Failures
- Erosion Related Failures
4Fatigue Failures
- Fatigue related failures can occur due to cyclic
bending action such as thermal expansion and
contraction in headers
5Thermal Fatigue Cracking Failure at Toe of
Extended Surface Boiler Stub to Header Weld With
Resulting Header Erosion Damage
6Thermal Fatigue Cracking at the Toe of
Superheater Outlet Stub to Header Weld
7Thermal Fatigue Cracking Failure in Slag Screen
Tube Approximately 1 Out From Toe of Seal Weld
at Drum Penetration
8Overheating Related Failures
- Overheating failures can occur due to chronic or
acute overheating situations
9Creep Failure in Superheater Tube Due to Chronic
Overheating (T-22 Material)
- Chronic Overheating Can Be Caused By Improper
Superheater Temperature Control
10Creep Failure in Superheater Tube Due to Chronic
Overheating (T-22 Material)
11Hot Tensile Overload Failure
- Hot Tensile Overload Failure Can Result From Loss
of Circulation in Water Wall Tubes With Resulting
Acute or Chronic Overheating of the Tube
12Erosion Related Failures
- Erosion Related Failures Can Occur Due to Fly Ash
Erosion or From Steam and/or Water Induced
Erosion
13Thin Lipped Failure of Water Wall Tube Due to
Soot Blower Steam Erosion
14Superheater Header Erosion Due to Steam Jet From
Thermal Fatigue Crack
15Flow Induced Erosion/Departure From Nucleate
Boiling Failure In Extended Surface Boiler Tube
16Thin Lipped Rupture Due to Flyash Erosion on
Water Wall Tube Awarded to Rent-A-Maintenance-Mana
ger Claude Smith Smitty