Which work performed on a boiler does not need to be reported and is considered exempt?

The replacement of backings to the manholes and hand holes is considered exempt from reporting requirements because it typically does not affect the overall integrity or safety performance of the boiler system. This kind of maintenance is often routine and is seen as part of regular upkeep that ensures the boiler remains operable without necessitating extensive documentation or reporting to regulatory agencies.

In contrast, the other options listed involve more significant alterations or inspections. For instance, replacing the entire boiler is a major undertaking that typically involves structural changes and compliance with safety codes, hence it requires thorough reporting and inspection. Similarly, replacing gaskets can impact sealing and pressure integrity, necessitating detailed records to ensure the boiler operates safely. Inspections are critical for safety compliance, requiring documentation to verify that the boiler meets regulatory standards. Thus, these activities are not exempt and must be reported as they relate to the overall safety and operational integrity of the boiler system.