What type of maintenance involves checking for leaks and overall integrity?

The correct choice focuses on the process of assessing the overall condition and reliability of a boiler system, which is essential for safe operation. Structural integrity inspection specifically targets the examination of physical components for any signs of wear, corrosion, or damage that could lead to leaks or failures. This type of maintenance is crucial because identifying and mitigating issues related to structural integrity directly impacts the safety and efficiency of the boiler system.

In the context of boiler maintenance, structural integrity inspections often include checking welds, supports, and the overall framework to ensure that all aspects are in good condition. Monitoring for leaks is a critical part of this inspection, as even small leaks can lead to significant operational issues or hazards.

The other choices involve different aspects of boiler maintenance, such as performance auditing, which evaluates how effectively the boiler operates; water quality monitoring, which focuses on the chemical properties and cleanliness of the water used in the boiler system; and burner calibration, which ensures that the burner operates efficiently and safely. However, none of these directly pertains to assessing structural integrity or checking for physical leaks.