What condition does bulged metallic linings often indicate?

• A. Flaws in the welding process
• B. Leaking liner or differential thermal expansion
• C. Presence of foreign materials
• D. Brittleness due to aging

Answer: (B)

Bulged metallic linings are often indicative of a leaking liner or differential thermal expansion. When a pressure vessel experiences a leak in the liner, it can lead to the accumulation of fluids between the lining and the base material, creating pressure that causes bulging. This bulging can also occur when there is differential thermal expansion—if the lining expands at a different rate compared to the shell of the vessel due to temperature variations, it can lead to deformation. This condition is critical to identify, as it can compromise the integrity and operational safety of the pressure vessel.

Addressing this issue involves closely monitoring for signs of exposure to corrosive substances, improper thermal management, or mechanical stresses that may lead to such bulging conditions. Understanding these factors is crucial for maintaining the longevity and safety of the vessel.