Risk-Based Inspection

Equipment availability and the safe, efficient operation of aging infrastructure are key to profitability in the refining industry. So it's not surprising that more and more refiners are making Risk-Based Inspection (RBI) an integral part of their plant work process. Why? Because RBI refocuses inspection dollars and critical related efforts where they're needed most, using risk as a basis for prioritizing and managing an in-service inspection program. This is accomplished by technology that considers the probability and resulting consequences of an undesirable event.

A relatively large percentage of risk in an operating plant is associated with a small percentage of the equipment items. RBI permits the shift of inspection and maintenance resources to provide a higher level of coverage on the high-risk items and an appropriate effort on lower risk equipment. A potential benefit of a RBI program is to increase operating times and run lengths of process facilities while improving, or at least maintaining, the same level of risk. RBI helps plant maintenance personnel focus resources, target inspection dollars and control costs by factoring risk into inspection planning and management.

Equity Engineering’s Lynne Kaley, P.E. is an internationally recognized industry expert and leader in the development and use of Risk-Based Inspection technology. She has been actively involved in the API RBI development project since the start, and has been the Project Manager of the API RBI User Group since 1996.

Download Risk-Based Inspection Brochure (PDF)

API RBI: The only official RBI technology and software

rbiThe RBI methodology and software developed by the American Petroleum Institute Joint Industry Project (API JIP) has become the industry standard for implementing Risk-Based-Inspection. API RBI has been or is being implemented in refineries worldwide, and most of the major U.S. refiners are members of the API RBI User Group.

The API RBI JIP has made major advancements since the publication of the initial document, and completed a re-write of API 581 to capture new technology developed by the JIP. This second edition of API 581 provides a logical, step-by-step procedure that enables practitioners to better understand the methodology, and makes the technology clear to facilitate an effective peer review. The 581 Recommended Practice is titled Inspection Planning Using API RBI Technology to emphasize the fact that significant technology, including industry best practices, is required to effectively implement an RBI program. This second edition of API 581 presents the API RBI methodology in a 3-part volume:

Part 1 – Inspection Planning Using API RBI Technology

Part 2 – Determination of Probability of Failure in an API RBI Assessment

Part 3 – Consequence Analysis in an API RBI Assessment

API RBI technology is thoroughly documented in API 581, available for purchase from API. The API RBI software is a validation of solid technology, as its output is tested against this documentation for accuracy. This documentation is what differentiates API RBI from its competitors.

Various companies have developed RBI approaches based on API 580, but most tend to be "black-box", or they are too generic to accurately define an auditable inspection / maintenance plan that measures inspection program improvement. While others may focus on aesthetics, the primary goal of API and E2G is sound technology – producing PoF, CoF and risk numbers you can trust.

The API RBI Software Difference

Developed by subject matter experts from top refiners and backed by a prestigious industry association, API RBI software technology reflects industry best practices and the expertise of the best minds in the industry. The most comprehensive risk assessment and management tool on the market today, it includes:

  • Numerous technical modules to calculate corrosion rates and damage susceptibilities developed by consensus groups’ corrosion and materials specialists
  • New state-of-the-art fluid property modeler completely rewritten to use improved algorithms that are more robust and accurate to calculate the properties of two-phase fluid mixtures (recipes) over a wider range of operating conditions
  • User-defined process streams created from a fluid property database of over 1,800 fluids compiled from such sources as the industry-standard DIPPRR database, which is regularly tested and updated for accuracy
  • Outputs that include both the qualitative risk matrix and quantitative data expressed in risk per unit area per year and/or financial risk, in addition to numerous risk, PoF, CoF reports and the inspection plan
  • For each component, risk-weighted damage curves for each damage mechanism to show when that mechanism's contribution to end of life shifts - important for developing equipment end of life strategies or assessing operating condition changes
  • Ability to provide quantitative output, such as risk in ft2/yr (or m2/yr), enabling the user to compare risk reduction for a component, group of components, or unit to the amount of money spent on the fixed equipment reliability program, or the cost of repair or replacement
  • Most extensive materials properties electronic library available for associating each component with the appropriate year of the appropriate code for Tmin calculations

API RBI software includes comprehensive modules for Pressure Relief Devices (PRDs), Atmospheric Storage Tanks, and Heat Exchanger Bundles. Other modules are now being developed.

'Best in Class' linking capabilities

API RBI software seamlessly integrates databases and planning practices. The software is built on open architecture, providing the capacity to link to almost any software tool including MySQL, Oracle, and SQL server. This 'Plug & Play' approach allows users to link to existing tools and databases without requiring them to change products or pay additional license fees.

Users can take advantage of 'Best in Class' programs such as Meridium, UltraPipe, PCMS, SAP and various CMMS programs, and not be restricted to a 'one size fits all' software that produces answers with wide scatter bands. Solutions can be customized to platforms to suit your needs, providing maximum flexibility, data migration and mining and engineering predictive effectiveness.

Managed links with leading vendors of asset performance management software are available. These companies have created integrated modules that enable API RBI and inspection database management tools and results to be shared, leading to a more comprehensive Mechanical Integrity Program.

Download API RBI V8 Software Fact Sheet (PDF)

After the RBI Study

It is important to maintain and update a RBI program to ensure that the most recent inspection, process, operations and maintenance information is included. Optimally, RBI should be combined with Fitness-for-Service and Materials/Corrosion disciplines to manage equipment integrity through the useful life of equipment. These follow-on activities will help improve the quality, accuracy and value of an RBI study.

File Upgrades

Conditioning and converting files to the latest database version includes new data entry, validation and analysis, and developing a new inspection plan.

Five-Year RBI Evaluation

API 510 and 570 Codes require re-evaluation of a RBI study at a maximum frequency of 10 years. However, for maximum safety and program benefit, E2G recommends re-evaluation in five years. The results of inspections, changes in process conditions, and operating outside of identified key process variable ranges can each have a significant effect on corrosion/cracking rates and PoF and trigger the need for a reassessment.

Evergreening

RBI Evergreening, the continuous updating of the RBI files and associated equipment inspection plans, maintains and updates your RBI program to ensure that the most recent inspection, process, operations and maintenance information are included.

Data updating of a current inspection history is usually performed in conjunction with turnaround work; during the Management of Change (MOC) process; to comply with OSHA 1910 HAZOPs, PHAs or audits; or after an unexpected failure. Evergreening updates the following data:

  • Inspection History – date of inspection and measured thickness (internal/external thinning), inspection effectiveness grade by mechanisms
  • Measured corrosion rate representative for the circuit/corrosion group; modifications in cracking susceptibilities, as appropriate
  • Any significant findings from inspection

Once the RBI date and inspection plan date are reset, risk is then recalculated.