TABLE OF CONTENTS Within a typical world-class industrial commodity chemical company, the annual cost of maintenance is 3 to 6 percent of the asset replacement costs. A number of significant maintenance activities require very little interruption of continuously operating chemical plants. Everyday maintenance activities that may be accomplished on a routine basis include repairs to a spare pump or spare compressor after it has been properly isolated and cleared of fluids, and overhaul of a fully spared filter or painting.
However, other preparations for maintenance activity that seem innocent can jeopardize or ruin equipment and result in injury. Trevor Kletz has often discussed problems of preparation of maintenance. Recently, Kletz wrote:
Maintenance is a major source of accidents, not so much the maintenance in itself but the preparation of equipment for maintenance. Sometimes the procedures are inadequate; sometimes the procedures are satisfactory but not followed. In particular:
The equipment to be repaired may not be isolated from sources of danger such as pressure as pressure or hazardous chemicals.
The equipment may not be identified so that the wrong equipment is opened up.
The equipment may not have been freed of dangerous materials and tested to make sure that it is free.
The maintenance workers may not have been warned of the residual hazards or advised what precautions to take: or they may not have taken precautions, even after the advice. [1]
This chapter covers examples of system modifications made to prepare for maintenance.
