Home » Boiler Tube Failure Handbook » Cracking » Not in or near a weld or attachment Observation: Cracking » Not in or near a weld or attachment Appearance Observation Locations Mechanism Circumferential cracking Cracking » Not in or near a weld or attachment » Transverse Waterwall Thermal Fatigue Short longitudinal cracks with numerous parallel cracks Cracking » Longitudinal » Not in or near a weld or attachment ReheaterSuperheater Long-term Overheat/Creep Multitude of cracks parallel to tube Cracking » Longitudinal » Not in or near a weld or attachment Superheater Long-term Overheat/Creep Longitudinal crack at bend Cracking » Not in or near a weld or attachment ReheaterSuperheaterWaterwall Long-term Overheat Appearance Observation Location Mechanism