Client Context
Mangalore Refinery and Petrochemicals Limited operates a large, integrated petroleum refinery handling a wide range of crude slates and downstream conversion processes. With assets commissioned across multiple phases and operating under varied temperature, pressure, and corrosive environments, inspection planning and integrity assurance are critical to sustaining safe and reliable operations.
To strengthen long term asset integrity and move away from purely time based inspection practices, MRPL initiated a structured transition to Risk Based Inspection (RBI) using the Cenosco Asset Integrity Management System (AIMS) software supplied by M/s Cenosco Custom B.V., aligned with internationally recognised API standards.
iFluids Engineering was engaged to execute RBI implementation for select critical refinery units, covering primary distillation, conversion, hydrotreating, polymer processing, and hydrogen services.
iFluids Engineering carried out RBI implementation for the following refinery units:
- Crude Distillation Unit – Phase I & II
- Continuous Catalytic Reforming Unit – Phase II
- Coker Hydro Treating Unit
- Delayed Coker Unit
- Polypropylene Unit
- Hydrogen Generation Unit – Phase III
- Diesel Hydro-desulphurization Unit
These units represent some of the most integrity critical services within the refinery, including high temperature fractionation, high severity hydrogen service, delayed coking, hydrotreating, and polymer processing.
The Integrity Challenge
Prior to RBI implementation, inspection planning across these units was largely interval based, supported by extensive historical thickness measurement records maintained in hard copy formats. While the data volume was significant, it lacked structured linkage to:
- Process operating conditions
- Damage mechanisms specific to service severity
- Risk based prioritisation of inspection effort
Additionally, corrosion loop definitions and inspection focus areas varied between units, limiting the ability to apply a consistent, refinery wide integrity philosophy.
The objective of the engagement was to establish RBI as a practical, sustainable integrity management framework, embedded into day-to-day inspection planning rather than treated as a one time analytical exercise.
iFluids Engineering Approach
Corrosion Study and Corrosion Control Documentation
The work commenced with detailed, unit wise corrosion studies carried out in close coordination with MRPL’s inspection and process teams.
Key activities included:
- Identification of all credible damage mechanisms in accordance with API 571
- Development of uniform corrosion loops and circuits, ensuring consistency across all units under scope
- Integration of operating conditions, design data, materials of construction, and historical degradation trends
- Definition of Critical Process Variables and Integrity Operating Windows, aligned with API 584 requirements
Each Unit specific Corrosion Control Document was developed as an operational reference, clearly linking process conditions to corrosion threats and inspection requirements. Structured corrosion workshops were conducted to validate assumptions, corrosion rates, and loop boundaries before finalisation.
Drawing Digitisation and TML Engineering
A significant execution effort involved converting legacy inspection drawings into RBI ready digital assets.
iFluids Engineering performed:
- Conversion of piping isometrics and equipment general arrangement drawings from scanned and PDF formats into AutoCAD models
- Amalgamation of multiple isometric drawings into single, circuit level representations for complex services
- Engineering based Thickness Measurement Location optimisation, considering flow regime, damage susceptibility, and inspection effectiveness
- Definition of appropriate measurement points for fittings, reducers, elbows, and vulnerable geometries
All thickness measurement locations were reviewed with MRPL and approved prior to migration into the RBI system.
Historical Data Consolidation and AIMS Configuration
Decades of historical inspection data formed the backbone of the RBI model and required careful engineering validation.
iFluids consolidated and structured:
- Historical thickness measurements from hard copy records
- Equipment and Piping metadata
- Injection point information
- Spring support details
- Historical failure and repair records
The data was cleaned, validated, and uploaded into the Cenosco AIMS platform using system specific templates. Thickness trends, alert limits, and retirement thickness calculations were reviewed to ensure RBI outputs were technically robust and traceable.
RBI Modelling and Inspection Strategy Development
Using the configured AIMS environment, iFluids carried out semi-quantitative RBI assessments in compliance with API 580 and API 581.
The RBI scope included:
- All static equipment and piping systems within the Units under scope
- Associated valves, flanges, filters, safety devices, and underground piping
- Integration of historical failure data into probability of failure calculations
- Consequence modelling based on process inventory, operating pressure, and service severity
Risk matrices were developed for each unit, followed by structured risk review workshops with MRPL. For every corrosion loop and equipment item, risk based inspection plans were developed, clearly distinguishing between online and offline inspection requirements and optimised inspection intervals.
This engagement reflects iFluids Engineering’s approach to delivering Risk-Based Inspection (RBI) services ↗ as a practical integrity management system rather than a standalone study. The scope covered corrosion studies, corrosion loop development, historical inspection data consolidation, and semi-quantitative RBI modelling in line with API 580 and API 581 requirements. The same methodology is applied across Refinery and Process Industry engagements, where RBI outcomes are directly translated into inspection planning and long term asset integrity decision making.
Outcomes Achieved
The RBI implementation delivered measurable integrity improvements, including:
- A consistent corrosion and RBI framework across the executed Refinery units
- Risk ranked inspection planning focused on credible degradation threats
- Digital inspection records integrated into a sustainable asset integrity platform
- Improved visibility of high risk circuits in severe processing services
- A practical transition from time based inspection to risk informed decision making
Most importantly, the RBI system was embedded as a living integrity tool, owned and actively used by MRPL inspection teams.
iFluids Engineering Value Contribution
The engagement was characterised by strong technical ownership and execution discipline, including:
- Robust corrosion engineering input during loop definition
- Hands-on involvement in data consolidation and validation
- Inspection strategies aligned with real operating and maintenance constraints
- Continuous engagement through workshops, reviews, and implementation support
Conclusion
The successful RBI implementation across critical refinery units demonstrates iFluids Engineering’s capability to deliver large scale, refinery-grade RBI programs that integrate corrosion science, inspection engineering, and risk-based planning into a sustainable asset integrity framework.
This engagement stands as a reference for executing end-to-end RBI implementation in complex refinery environments, where technical depth and execution rigour are equally critical.
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