Rules of Risk-Based Inspection of Complete Units—Part 4: Parabolic Trough Solar Thermal Power Plants

This document applies to the inspection of pressure-bearing equipment in parabolic trough solar thermal power plants that have implemented risk-based inspection projects; other types of solar thermal plants may refer to it, while safety valve inspection is excluded. It specifies procedures for damage mechanism identification, risk assessment and development of inspection rules, covering solar collection, steam generation, molten-salt thermal storage, and turbine power-generation systems. Users shall identify potential damage mechanisms, including thermal fatigue, molten-salt corrosion, alkaline corrosion and erosion, according to actual operating conditions; quantitatively analyse likelihood and consequence of failure, determine risk levels, and establish inspection timing, scope, type, methods and critical locations accordingly. Where damage or defects are found, inspection shall be expanded or handled in accordance with relevant standards and specifications.