Risk-based Analysis Tools

American Society of Mechanical Engineering’s (ASME) risk-based inspection methodologies are being used to optimize and prioritize equipment overhaul and maintenance, and upgrade decisions. Hartford Steam Boiler Inspection and Insurance Co. (HSB) collaborated with ASME in developing these guidelines, and it used the ASME methodologies to develop its risk-based decision tools for steam turbine generators. The ASME Risk-Based Inspection Guidelines define five primary steps in developing risk-based programs. These are system definition, qualitative risk assessment, system assessment ranking, inspection program development, and economic optimization. In order to differentiate between turbines and generators in several types of service, the team designed a questionnaire that requires the owner or operator to identify equipment design features, monitoring capabilities, past operating and failure history, as well as current operating experience, inspection, and maintenance practices. The STRAP program is presently in the beta-testing phase, where 30 different turbines representing eight different manufacturers and three different industries have been analyzed. Full implementation of the program is expected to occur in the fall of 1998.