Authors: Gaffar Mirzoev, Dr. Gaurav Singh
Risk-Based Inspection in Right Timing
Digitalizing risk-based inspections with the NIMA platform solution
In a Nutshell:
The common goal that unites us is the pursuit of zero incidents. Embracing our role in this, we dedicate our expertise as the world's largest team of pipeline integrity specialists to empowering operators in effective decision-making. We leverage out integrity knowhow and the practical, proven methods developed working with operators worldwide. And that is exactly where our asset integrity management platform NIMA comes into play. It offers operators certainty in their asset integrity management (AIM) process. Find out more in this article about how to digitalize risk-based inspection using our NIMA platform.
What becomes more and more the focus of asset integrity is concentrating on the generation of inspection programs that improve operator knowledge about the damage state of their equipment; doing so, we can reduce uncertainty and clearly define the level of risk.
The NIMA risk-based inspection (RBI) approach has been developed based on the guidance given in API Recommended Practices 580/581, with a focus on exactly those inspection programs. Our NIMA process-based workflow allows users to move towards risk-based inspections and monitoring of their assets. The current practices are either based on fixed-interval (time-based) inspection regimens or condition-based monitoring, where calculations are made for corrosion rates and thought is given to damage progression and damage mechanisms.
Just the right timing
ROSEN won its first NIMA RBI digital integrity systems project in Central Asia in 2021. The client is one of the major leading manufacturers of polymer products in the region, with a high level of natural gas processing technology. The facility to be assessed using our integrity management platform consisted of five main plants:
- A gas separation plant
- An ethylene production plant
- A polyethylene production plant
- A polypropylene production plant
- An energy supply plant
An international audit company – a global leader in insurance broking and risk management for major industries – laid down the key recommendations for the client going forward. Those included the implementation of the RBI software approach based on API 580/581 in order to carry out inspection planning and maintain the integrity of the assets in the facility by predicting failures and incidents, as well as maintaining the data in a central repository where it can be traceable, verifiable, and in compliance with local and international regulations.
The client contacted ROSEN to confirm that our NIMA solution indeed offers RBI functionality. The timing was just right: at that point, the newly developed RBI templates were being quality checked and finally approved, so we were able to meet the client's requirements.
What the risk-based inspection approach includes
The NIMA RBI implementation includes a NIMA Integrity Management Platform (standard on-premises implementation) with RBI functionality and provides access to the NIMA RBI library with standard process templates available for the customers without any further configuration being necessary. The standard process templates being "Risk", "RBI for Pressure Vessel and Piping", and "Risk, RBI for Atmospheric Storage Tanks". Currently available in both English and Russian, the NIMA user interface will be supported in additional languages in the future.
Pressure vessels and piping process template
The “Pressure Vessels and Piping” process template provides quantitative risk-based inspection assessment per API RP 581 Risk-Based Inspection Methodology (3rd Edition – Addendum 1) and outlines inspection programs using risk-based methods for the pressurized fixed equipment listed below:
- Pressure vessels (column, drum, filter, knock-out drum, reactor, sphere)
- Heat exchangers (shell side, tube side and top side)
- Air fin heat exchanger header boxes (fin fan cooler)
- Piping (NPS from 1 to 16 and greater than 16”)
- Compressors and pumps (reciprocal and centrifugal pump casing, reciprocal and centrifugal compressor shell)
Scope of current RBI templates
The current version of the template covers calculation of probability of failure (PoF) and consequence of failure (CoF) Level 1 as well as risk evaluation (risk matrix and ISO risk plot) and inspection planning based on a maximum tolerable risk or maximum probability of failure value input by the user.
Currently, the development covers the following damage mechanisms specified in API RP 581:
- Component internal lining
- External corrosion – ferritic component
- Corrosion under insulation (CUI) – ferritic component
- Piping mechanical fatigue
- Brittle fracture
- Stress-corrosion cracking (SCC) – caustic cracking
- Stress-corrosion cracking (SCC) – sulfide cracking
Atmospheric Storage Tanks Process Template
NIMA's "Atmospheric Storage Tanks" (ASTs) process template provides quantitative risk-based inspection assessment per API Recommended Practice 581 Risk-based Inspection Methodology (3rd Edition – Addendum 1) and outlines inspection programs using risk-based methods for tank bottom and tank shell courses.
This template covers calculations of probability of failure (PoF), consequence of failure (CoF) Level 1 as well as risk evaluation (risk matrix and ISO risk plot) and inspection planning based on a maximum tolerable risk or maximum probability of failure value input by the user.
Actual corrosion rates are calculated from inspection thickness reading for both tank bottom and shell courses. In addition, theoretical corrosion rates are estimated for soil side and product side, as specified in Annex 2B of API RP 581, when inspection data is not available.