TABLE OF CONTENTS Omitting so-called corrective (or, as it is sometimes termed, reactive) maintenance necessarily carried out in cases of sudden failures, the most conventional practice of maintaining large power steam turbines is their preventive maintenance (PM), which includes regular, previously scheduled inspections, repairs, overhauls, and replace ments. The goal of PM is to reveal accumulated damages, remove them and their consequences, and provide reliable operation until the next scheduled inspections and repairs. It is also intended to restore the turbine efficiency deteriorated in the course of previous operation.
In recent years in the power industry, there have also been increasingly frequent appeals for a transition from traditional PM to so-called predictive maintenance (PdM), also known as condition-oriented maintenance (COM), reliability-centered maintenance (RCM), and efficiency-oriented maintenance (EOM). With PdM, the operated equipment is stopped for repairs not on a regular calendar basis, as with PM, but only if the equipment condition has significantly changed for the worse, and further operation is either dangerous in terms of reliability or unprofitable in terms of efficiency. [1]
This kind of maintenance, which is presently applied more and more frequently in different fields of industry, is based on the intense use of technical diagnostics, continuous monitoring, and analysis of stored operating performance data. All of these measures should provide a possibility of continually evaluating current equipment condition and its changes during the operation process and revealing any imminent failure at a very early stage. The more complicated the operated equipment is and...
