Home » Boiler Tube Failure Handbook » Pulp and Paper Industry: Pulp and Paper Filter Items by: Observation Location Mechanism Appearance Observation Locations Mechanism Bulging tube adjacent to field weld Deformation » Bulging Waterwall Long-term Overheat Metal thinning on fireside Deformation » Thinning WaterwallSuperheater Smelt/Slag Attack Porosity in weld Material Defect » Holes, Pits, Gouges Superheater Weld Defect Fine cracks around studs Cracking » Transverse » Not in or near a weld Studded Waterwall Thermal Fatigue Multiple cracks associated with attachment on outside of tube Longitudinal or Random » Cracking » In or near weld or attachment WaterwallEconomizer Corrosion Fatigue Cracks close to attachments Cracking » In or near weld or attachment » Longitudinal Waterwall Corrosion Fatigue Bulging tube adjacent to field weld Bulging » Deformation Waterwall Long-term Overheat Appearance Observation Location Mechanism
