NDTnet 1998 Aug, Vol.3 No.8

Abstract

Description
The term Risk Based Inspection (RBI) has been used for many years within the industry in general, and has more recently been adopted for larger development projects, such as those used by American Society of Mechanical engineers, (ASME) and The American Petroleum Institute (API). This concept has been further developed for offshore systems where RBI has been customised to utilise existing safety and reliability analysis i.e. QRA and RAM.The purpose of RBI are a) to rank all process components according to risk, b) to indicated the time to next inspection and c) perform a cost optimisation based on risk. The probability of failure has been determined by combining expertise in materials technology with information about the damage tolerance for a given component. It is important to appreciate that the estimation of failure probability and appropriate inspection intervals are strongly influenced by the inspection efficiency, i.e. how good a given inspection technique is for detecting the "worst" damage, when applied to a given component/system with a given coverage.

Application
A methodology has been developed to cover topside systems, risers and pipelines. The paper will primarily address on topside systems. RBI will be described in the context of overall inspection management for a plant.

Results and significance
Case studies applying these principles have shown large savings in inspection volume - in one case between 25 and 40 % compared to the previous plan. In this case the RBI analysis have been an efficient tool to identify the high risk items that needs high attention as well as the low risk items that can be handled on a 'repair' basis.

Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00

Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:

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