The in-service boiler or HRSG inspection has the advantage of being able to be conducted at nearly any time. It encompasses the external components and typically refers to a unit that is running (or “hot”), but can also encompass a unit that is ready to run and in standby.
The in-service hot inspection aims to check for (steam, water, air, exhaust) leaks , hot spots, mechanical damage, unusual movement and excessive noise or vibration on the boiler piping, casing, air/exhaust ductwork as well as associated vessels and drums. The usual techniques used are visual observation and thermography. In some cases Tetra Engineering may suggest more elaborate techniques as an option, such as installing thermocouples or vibration sensors to gather data for a particular known problem issue.
Besides the field inspection, an effective in-service inspection requires an examination of process data for the time of inspection and for a representative interval (such as several months) preceding that time. This provides the Tetra inspector with useful context for comparison with the conditions that were observed in the field.
Stay up to date and refer to our large collection of technical white papers and articles
Idle periods are getting longer as plants move to cycling or standby, and corrosion during layup can do serious damage. Pitting can penetrate a tube wall in a few weeks. In the October 2026 issue of Modern Power Systems, Misha Gadher and James Malloy of Tetra Engineering Europe compare five preservation methods and show how one coastal combined cycle plant matched each method to each system for a six-month shutdown.
