Risk-Based Inspection as a Reliability-Engineering Tool for Fixed Equipment Decisions

Risk Based Inspection (RBI) results in calculating a risk value for each piece of plant fixed-equipment. Usually RBI implementation results in fixed-equipment inspection program modification. Inspection is specified for equipment items that exceed Owner acceptable risk criteria while it is waived for equipment that is below acceptable risk levels. In RBI analysis, equipment risk value consists of a Likelihood-of-Failure (LOF) and a Consequence-of-Failure (COF) element. Furthermore LOF value is the sum of different equipment damage mechanisms (internal corrosion, external corrosion and cracking mechanisms). This paper describes on Olefins plant gains from applying RBI as a reliability-engineering tool instead of an inspection optimization tool. Based on RBI calculated risk values, fixed-equipment relative risk ranking is established to: • set priorities and focus our attention on the critical areas; • justify capital investment for Lifetime Extension projects; • proactively address Loss of Primary Containment and Process safety issues.