American Petroleum Institute

Guide for Inspection of Refinery Equipment - Chapter XV-Instruments and Control Equipment - Third Edition
 N IRE C15

Annotation

The primary purpose of this chapter is to present a guide for instrument inspection. It is not intended as a maintenance manual. However, the inspection procedures suggested can be used in a preventive maintenance program. These procedures cover the majority of types of standard commercial instruments and associated equipment used in modem refineries. Particular attention is given those instruments which affect safety and continuity of operation.

Instruments are classified according to type of measurement or function performed. Since the inspection of many instruments includes checking transmission systems, power supplies, seals, purges, panels, and other associated equipment, such equipment is also discussed.

Refinery operations are, to a great degree, dependent upon accurate and reliable instrumentation. Measurement and control systems can be relied upon only if they are inspected periodically and serviced by competent, specially trained personnel who are familiar with both process requirements and instrument functions. Throughout this chapter, the use of the term inspector shall be construed to mean a person or persons qualified to perform the instrument inspection.

In plants having separate instrument departments where the instruments are not normally inspected by the regular plant inspector, the instrument inspector and the plant inspector should collaborate in the inspection of control valves, level-float cages, instrument air and hydraulic systems, and similar instrument equipment where metal thickness measurements or pressure testing are required. For recommendations on proper installation of instruments, reference should be made to the various sections of API RP 550. This chapter outlines only equipment that requires inspection, develops the methods and frequency of inspection, and discusses records and reports that should be maintained on the various types of instruments and systems. The types of equipment requiring inspection are classified in this publication as follows: