Air operated valve maintenance at Bruce 'A'

In 1990, a new Air Operated Valve(AOV) diagnostic tool was demonstrated at Bruce A. During the demonstration, the diagnostic unit quickly and correctly identified a passing valve that had extended a unit outage by five days. As a result of the demonstration, Bruce A began a pilot program in 1991 to assess the condition of critical station AOV's and to lay down the framework for developing an AOV Preventive Maintenance (PM) program through the use of state of the art valve diagnostics. This paper will begin by focusing on the key elements of the program including program goals, division of responsibilities, work flow and quality assurance. The focus will then shift to a discussion of the results of over 1000 diagnostic tests that have been performed at Bruce A. The trends observed in the results will be explored to identify those areas of AOV maintenance which should be targeted. The data will also be analyzed to demonstrate the effectiveness of the program in the areas of reduced corrective maintenance and reduced maintenance rework. The results of recent program review are also presented to complete the discussion of the program's effectiveness