What constitutes a major repair?

A major repair is defined as a significant alteration or restoration that impacts the integrity and functionality of a system, especially regarding safety and performance. Structural modifications that affect pressure boundaries are critical in this context because they directly relate to the safe operation of systems that operate under pressure, such as piping or vessels in various industries. These modifications can involve reinforcing structures, redesigning pressure vessels, or changing component connections to ensure they meet safety regulations and operational standards.

This is distinctly different from other activities like replacing worn parts, which may maintain operational functionality but do not fundamentally alter the structure or pressure integrity. Regular maintenance operations and routine inspections focus on upkeep rather than substantial modifications, and they typically do not require major changes or re-evaluations of safety codes. Therefore, the emphasis on structural modifications affecting pressure boundaries as a major repair highlights the critical nature of maintaining safety and reliability in engineering practices.