An Approach for Analysing Boiler Tubes Ultrasonic Inspection Data to Support Decision Making

There is now much interest in the development of risk based strategies for maintenance planning including assessing appropriate inspection strategies and making economic life estimates of critical components. This study examines this problem from a practical point of view by studying a significant body of tube thickness inspection data collected in a power station. This data naturally has all sorts of difficulties. For example there are issues related to the accuracy and correctness of the measurements. Then there is the issue of how to use the data to determine deterioration rates and life expectancy. This paper examines this data using: • a method developed by the authors: a procedure based on a “warning level” approach, and • a suggested interpretation of the American Petroleum Institute’s technique of “risk based inspection”.