Careers Mitigate Aggressive Corrosion from Process Changes in Fractionation Columns
One of Egypt’s key refineries, operating complex downstream units, faced an operational challenge with a Crude Distillation Unit (CDU). A 10-year-old atmospheric fractionation column (Figure 1) and an accompanying precut column (Figure 2) had been taken out of service due to changes in process chemistry that rendered the original metallurgy insufficient. The new operating environment was far more aggressive, requiring a durable corrosion solution to safeguard critical internals and enable a successful restart.
The objective was to restore operability, avoid capital expenditure on new equipment, and implement a corrosion mitigation strategy that would withstand severe service conditions at approximately 300°C and 3.5 kg/cm². The columns included complex internals like tray supports, brackets, and nozzles, all of which required corrosion protection to accommodate process changes safely.
T21-15571 & T25-43723
Reducing Long-Term Risk and CAPEX Exposure
Initial considerations included complete vessel replacement or lining with Corrosion Resistant Alloys (CRAs) during manufacturing, a process that would have taken over 12 months and incurred significant capital outlay. Weld metal overlay was also evaluated but ruled out due to longer application time, high heat input, risk of vessel distortion, and the requirement for post-weld heat treatment (PWHT).
Ultimately, the refinery selected IGS for its proven HVTS® (High Velocity Thermal Spray) metal alloy cladding technology, specifically designed for fast, cold-applied protection of large process vessels operating in highly corrosive conditions.
Solution Delivery
IGS deployed its proprietary HVTS cladding system, combined with surface conditioner, across the entire internal surface of the Fractionation and Precut Columns. A total of 662.5 m² was clad:
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630.0 m² in the Atmospheric Fractionator Column, including the internal shell, tray supports, nozzles, and downcomers
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32.5 m² in the Precut Column, including tray rings and brackets
The application was completed on schedule and significantly ahead of what a welded solution or new column fabrication would have required. The HVTS process introduced no heat stress or distortion to the base material and allowed safe application even in confined space conditions.
Quantifiable Impact and Proven Results
By selecting HVTS cladding, the refinery significantly accelerated its path to operational readiness while avoiding delays associated with new equipment procurement:
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12× faster turnaround compared to fabrication and delivery of a new CRA-clad column
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Cladding completed in just over five weeks versus an estimated 12+ months
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Zero safety incidents recorded during execution
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Critical CDU assets returned to service after 10 years, enabling production to resume far ahead of any alternative timeline
The speed and efficiency of the IGS solution ensured that vital refinery throughput was restored within a single turnaround window, mitigating corrosion risk without disrupting production targets.
“This has been another successful project. The plant is very pleased with our professionalism and the results we have achieved. The column is now in service after ten years and we have significantly extended the lifetime of the refinery’s mission critical equipment in a cost and time efficient manner. IGS has been called upon to inspect other crude distillation columns during the plant’s next shutdown.”
– Mohamed Al Ahwani, General Manager (Saudi Arabia & Egypt), IGS
Vessel restored to service, avoiding 12 months of production delay.
That’s Asset Vitality.
WATCH: How Do You Maintain Mission-Critical Assets Between Turnarounds?
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