MAY 2021 | Volume 100 Number 5 HydrocarbonProcessing.com 8 18 SPECIAL FOCUS: MAINTENANCE AND RELIABILITY 19 Cleaning distillation column and heat exchangers through cutter stock circulation L. Özkan, İ. Aydin and G. Öztürk 23 Stability evaluation of hot spots in the RDS process reactor S. M. Lee, S. H. Bae and D. S. Lee 29 An investigation into pressure vessel fatigue cracking caused by a tack weld A. Gupta, M. Al-Muwail, R. Donnelly and J. Nicholas 35 Restaging/rerating of centrifugal compressors: Fundamentals, practices and challenges DEPARTMENTS 4 Industry Perspectives 8 Business Trends 85 Show Preview 87 Innovations 89 Advertiser Index 90 Events COLUMNS 7 Editorial Comment Maintenance and reliability: A cornerstone of safe and efficient plant operation M. Ramalingam and B. Chandragupthan 43 How maintenance and reliability in gas analysis supports hydrocarbon processing installations M. Calvert 45 VALVES, PUMPS AND TURBOMACHINERY 57 Use infrared thermal imaging for pump system condition monitoring and early failure detection K. Brashler and Y. Alshahrani 61 Ensuring safety in dynamic chemical manufacturing environments S. Knecht HEAT TRANSFER 63 Double-tubesheet heat exchangers: Necessities and challenges P. M. Misal PROCESS CONTROLS, INSTRUMENTATION AND AUTOMATION 69 Improved measurement of water content in natural gas A. Garza and S. Miller 75 Implementation of averaging level control using native DCS functions G. Gous, P. de Vaal and G. van Coller ENVIRONMENT AND SAFETY 81 15 Quantum leap in chemical plant safety and reliability through mobile technology A. Murugan and V. Pattabathula Engineering Case Histories Case 112: Remote failure analysis consulting Thick-wall reactor shell repair procedure after damage detection at an interface in a hydrocracking unit S. Chidambaram Reliability Pushing the limit can have unexpected consequences Isentropic effects: Application and simulation E. Parvin and A. Robinson 50 13 17 Executive Viewpoint It was the best of times WEB EXCLUSIVE People Cover Image: Operators at a Saudi Aramco facility. Photo courtesy of Saudi Aramco.http://www.HydrocarbonProcessing.com http://www.hydrocarbonprocessing.com