Inspection optimization based on risk based approach

Abstract

The American Society of Mechanical Engineers has issued guidelines for methods using risk based information to develop optimization of inspection and maintenance. These guidelines have been applied to a thermal power plant data to develop optimization of maintenance and inspection. -- The optimization of maintenance and inspection is becoming increasingly important especially in oil fired thermal power plants as the fuel cost is on the rise. High production impact components such as, waterwall tubes, superheater tubes, reheater, forced draft fan, boiler feed pump, and condenser have been considered for developing component replacement optimization. An optimized inspection program has been developed for waterwall tubes. The financial implications of both maintenance optimization through component replacement and inspection optimization have been calculated in terms of Net Present Value for presentation to the corporate office. A link between the Engineering world and corporate world is established. -- This work begins at the analysis of field data of each component using Least Squares Approach to obtain Shape Factor and Characteristic Life for Weibull distribution. With the aid of Weibull distribution, probability of failure is calculated. Time ordered influence diagram is drawn for maintenance optimization. A decision model is developed to determine the maximum Net Present Value for the Optimization of Inspection. -- This work further demonstrates the application of ASME guidelines, Volume 3, (1994) 'Fossil fuel fired electric power generating station applications, Risk based inspection' to field data Weibull reliability model using Excel spreadsheets. This work has established a simple easy to use means of developing maintenance and inspection optimization.