Field Application for Development of Boiler Tube Inspection Procedure

The boiler, consisting of many tubes, is a core component in the operation of a thermal power plant. Damage to tubes leads to an increase in the maintenance cost which leads to the shutdown of the power plants. Therefore nondestructive inspections are routinely performed according to the maintenance plan. However, tube inspection mainly involves visual inspection, and additional thickness inspection is only carried out for abnormal areas. In a visual examination, the inner surface of the tube cannot be inspected. Hence, several cases of tube damage have been reported, which may be owing to the limitations of visual examination and the short duration of an overhaul. In this paper, we provide the results of a field test using various inspection techniques to develop a nondestructive inspection procedure that can quickly and efficiently inspect boiler tubes.