HRSG Desuperheater Failure After Seven Years Offers Maintenance Contractors a Hard Lesson
According to Inspectioneering Journal, engineers at Indian Oil Corporation documented a failure in an attemperator desuperheater at an industrial facility operating five heat recovery steam generator (HRSG) units, with the equipment having been in service for more than seven years before the failure was observed. The case study, authored by Chief Inspection Manager Manindra Pratap Singh and Inspection Manager Ayush Gangwar, appears in the May/June 2026 issue and examines how dynamic operating conditions, including frequent startups, shutdowns, and varying loads, can impose significant stress on desuperheating systems over time.
The technical lesson applies directly to US operations. Hundreds of combined cycle and cogeneration plants operate across Texas, the Gulf Coast, and the broader Southeast, many of them running similar HRSG configurations under the same cycling demands described in the case study. Maintenance contractors working these facilities are subject to OSHA Process Safety Management requirements (29 CFR 1910.119) and API 510 pressure vessel inspection standards, both of which place the burden of mechanical integrity on operators and their inspection contractors.
What It Means for Subcontractors
- Inspection and mechanical integrity contractors working on combined cycle or cogeneration facilities should treat desuperheaters and attemperators as high-attention items, particularly on units past the five-to-seven-year mark with heavy cycling histories.
- The case underscores the value of continuous monitoring of steam temperature, pressure, and control valve operation, areas where instrumentation and controls subcontractors can provide direct value to plant operators.
- The study highlights liquid penetrant examination and visual inspection as techniques used in identifying or assessing the failure. Qualified NDE crews offering these methods are well-positioned for HRSG maintenance programs, turnaround scopes, and mechanical integrity contracts across US industrial facilities.
