To meet legal and company-level requirements, a Risk Based Inspection (RBI) methodology is often introduced. The basis of this RBI philosophy is a corrosion study (a damage mechanism study). During such a study, all expected damage mechanisms in a plant are identified and the associated damage rates and failure modes for each piece of equipment are determined.
A corrosion study is a team effort that brings together the experience and knowledge of corrosion experts with inspection, process and maintenance personnel through team meetings.
A corrosion study identifies the possible degradation mechanisms per combination of material – medium – process conditions. In addition, a material degradation rate or susceptibility is determined. This allows a residual life of the installation to be estimated. The study can be performed on an entire plant, parts of the plant or a specific installation.
METALogic uses its own approach to perform a corrosion study in a qualitative and structured way. This approach of the corrosion study (also followed by RBI) has been translated into our own designed software package CorLife.
A corrosion study is the ideal start of an RBI strategy.
In a risk-based inspection strategy, inspection resources are deployed where they are most required. In other words, the inspection interval of a pipeline (or equipment part) is determined by the risk of failure. The risk of failure is the result of the probability of failure and the consequence of failure.
The outcome of the RBI study is an inspection plan which provides the following extensive information on each pipeline or equipment part. Inspection histories can also be easily retrieved via the software.