On line system monitoring and analysis for efficient maintenance management [Paper No.: I-10]

Continuously operating chemical plants and nuclear reactors with huge investments cannot afford unscheduled shut down, costly down time, undesired exposure of people to radiation and high cost of inventory. To obtain cost effectiveness in terms of increased plant availability with increased quality, safety and reliability of plant operations a good maintenance system is required. A preventive maintenance programme, though successful to a greater extent, has got the limitations of being based upon elapsed time, subjective approach or statistical data. Hence, maintenance action is mistimed. Preventive maintenance can become very effective if rational and scientific data on equipment under working conditions are available. It can be achieved through on-line predictive instruments like sound level and vibration analyzers, probologs, corrosmeters, strain gages, thermographic infrared sensors, on-line ferrographs, chromatographs, acoustic emission, eddy current ultrasonic and wireless sensors etc. Instruments help maintenance engineer to diagnose, inspect, monitor, and help in forecasting failures and scheduling the frequencies optimally for overhauls, replacements, lubrication etc. They are also helpful in establishing work load, manpower, resource planning and inventory control. This paper discusses real time computer based system as well as conventional instruments and techniques. (author)