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What is Risk-Based Inspection (RBI)?
Risk-based inspection (RBI) is a procedure in which industrial risks resulting from equipment or structural degradation are identified, assessed and categorised. This is done by an analysis of the probability and consequences of failure associated with each equipment, component or structure, a proper inspection and maintenance programme is then developed.
Why use RBI?
RBI is a powerful tool if carried out correctly, as part of a long-term strategy. It can be used to identify and understand risk, risk drivers, and where equipment is in its lifecycle. It can also indicate whether inspection is needed. RBI is important for optimising the operation and maintenance of industrial plants in various industries. It helps you to meet the financial, reliability and regulatory needs of the industry by improving your plant’s performance, availability and safety. It extends the lifetime of your plant by establishing a long-term testing and inspection procedure. RBI can be used to prioritize inspection-related activities, usually by means of non-destructive testing (NDT), in order to reduce the uncertainties around the true damage state of the equipment and the dynamics leading to such. The resulting inspection plan may outline the type and scheduling of inspection for an asset.
Process of Risk Based Inspection
The Risk based inspection process consists of the following steps:
Consultancy regarding all questions concerning the introduction of an RBI inspection and maintenance system
Assessment of status and history, remaining life and fitness for service, operational events, component reliability spare parts, resources and personnel
Determination of specific measures and flexible, adequate inspection intervals, considering financial and regulatory criteria
Development of optimised inspection and maintenance programmes in line with internationally accepted standards.
Implementation of industry-specific and customised solutions (including software application) for risk oriented lifetime management of system and components
Training the staff of the organisation on how to implement and operate the RBI system
RBI has quickly become one of the industry’s premiere instruments and preferred methods of inspection. The API 580 certification will add significant value to your professional credentials, demonstrating to your employers and clients that you have obtained a high level of proficiency and understanding in this very important field.
Risk Based Inspection – Condensate Pipeline
Corrosion is a major environmental deterioration phenomenon in chemical process industries affecting the life of process equipment and pipelines resulting in leakage, product loss, environmental pollution and loss of life. The overall risk associated with corrosion cracking in terms of its likely possibilities and its consequences to the plant and environment need to be addressed while designing the plant and before commencing regular operation. Corrosion risk analysis results should be used to formulate risk based inspection (RBI) procedures that should be a part of the plant operation. RBI concentrates inspection resources more on ‘High Risk’ and ‘Medium Risk’ assets and less on ‘Low Risk’ equipment. This paper gives two case studies dealing with oil and gas pipelines, preceded by a summary of the basic principles and procedures of corrosion risk assessment and RBI applicable to the Process Industries.
The paper has dealt with the principles of Corrosion Risk Analysis and Risk Based Inspection (RBI) as applicable to pressure parts of the oil and gas production, refining, petrochemical and chemical process industries. This was followed by a case study of an application of RBI for internal corrosion of an on-shore condensate pipeline. The importance of the criticality analysis within the RBI procedure, and the example of the specific case study were highlighted. It is concluded that RBI is a very effective method to assess risk and target inspection resources on critical items. When correctly implemented, the RBI approach is a powerful means of increasing the safety and reducing the inspection and maintenance costs of process plant equipment.