What is a common consequence of pitting in boiler metal?

Pitting in boiler metal is primarily a form of localized corrosion that can significantly weaken the integrity of the material. As pitting progresses, small, deep cavities form on the surface of the boiler metal, which can compromise its overall strength and structural integrity. This degradation can lead to cracks or ruptures under high pressure, thereby increasing the risk of a boiler explosion. When the metal is compromised due to such corrosion, it can no longer safely contain the steam and pressure built up within the boiler, making the system more susceptible to catastrophic failure.

In contrast, the other potential options do not accurately reflect the implications of pitting in boiler metal. Reduced pressure efficiency could result from various issues, but it is not directly a common consequence of pitting. Similarly, the statements about improved water circulation and enhanced heat transfer are misleading in this context; corrosion does not enhance these functions—in fact, it often has the opposite effect by disrupting flow and heat exchange properties. Therefore, understanding the risks associated with pitting highlights the critical need for proper maintenance and monitoring of boiler systems to ensure safety and efficiency.