TABLE OF CONTENTS The Maintenance volume is key to the Practical Guides Series and certainly a key to the profitability of companies through ensuring that the control system is maintained so the plant can produce its products. This volume includes some history and speculates about future advances of instrumentation and control (I&C) system maintenance; it also covers some of the fundamental principles, vocabulary, symbolism, standards, and safety. It suggests the necessary basic knowledge required of I&C technicians and the interaction of maintenance in the retrofitting and start-up of control systems.
From pneumatic instrumentation to computer-controlled systems what a change! Is a seasoned instrument mechanic expected to troubleshoot a state-of-the-art computer-controlled system? Should a new instrument technician be expected to maintain pneumatic instrumentation? This volume documents experiences in the older types of systems as well as in the newer, state-of-the-art systems.
Distributed control is not new. In 1938, when Chemical Processing published its first issue, mechanisms for control were indeed distributed throughout the plant. Process control consisted of operator adjustments to hand valves that were based on direct readings of local gages. Control room instrumentation has taken some dramatic turns along the way from large-scale pneumatic recorders to miniature analog electronic controllers to microprocessor-based digital systems.
Chemical and petroleum plants were among the first to use control systems for their processes. Pneumatic instrumentation became the leader in automatic control because of its safety. Pipe fitters were asked to perform maintenance on these early pneumatic instruments. In...
