• TECH TALK • ous erosion, thermal cycling, and process fluid contamination.
Regular inspection and testing programs, aligned with the requirements of API 598 and the manufacturer ' s recommendations, are necessary to verify that valves retain their specified sealing performance. Slide valves in particular require inspection of disc clearances and guide condition during each turnaround, with replacement of worn components.
As FCCUs age and are modified, reassessing isolation strategies are important to ensure they remain adequate for current conditions. This is particularly relevant in brownfield installations, where legacy designs may not meet modern safety expectations and where changes to feedstock composition, operating severity, or process configuration may have altered the hazard profile of the unit.
Management of change procedures must capture modifications that affect isolation system integrity, including changes to valve specifications, interlocking logic, and operating procedures.
Conclusion The isolation philosophy for Fluidized Catalytic Cracking Units has evolved into a sophisticated, risk-based discipline that integrates engineering design, operational practices, regulatory compliance, and human factors management.
The role of process safety management systems— including hazard analysis, management of change, operating procedures, and permit-to-work controls— in giving effect to isolation philosophy in practice is as important as the selection and specification of hardware.
By adopting and continuously improving a modern isolation philosophy, refineries operating FCCUs can better manage the inherent hazards of the process, protect personnel( and surrounding communities), meet regulatory expectations, and ensure reliable production of products throughout the operational life of these complex and indispensable units.
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* Ed Note: Point 4. Fractionator Section Isolation is continued from Part One of this article in Valve World Americas’ April issue.
• ABOUT THE AUTHOR •
Gobind Khiani has served in engineering management roles for both operating and EPC companies and has received Fellowship in Engineering. He has a bachelor’ s degree from the University of Pune in India and a Master of Engineering degree from the University of Calgary in Alberta, Canada. He is currently Secretary of CPGCE, Vice Chairman of International Standards Organization, and volunteers at API, AMPP( formerly NACE), ASME, CSA, CPGCE, ISA, ISO, MSS-SP, and PRCI representing Canada.
Valve World Americas | May 2026 | www. valve-world-americas. com 31