American Petroleum Institute

Manual on Installation of Refinery Instruments and Control Systems Part III - Fired Heaters and Inert Gas Generators
 N RP 550 P3

Annotation

FOREWORD

This recommended practice is based on the accumulated knowledge and experience of the more generally used measuring, control, and analytic instruments and related accessories to achieve safe, continous, accurate, and efficient operation with minimum maintenance. Although the information has been prepared primarily for petroleum refineries, much of it is applicable without change in chemical plants, gasoline plants, and similar installations.

Successful instrumentation depends upon a workable arrangement that incorporates the simplest systems and.devices that will satisfy specified requirements. Sufficient schedules, drawings, Sketchs, and other data should be provided to enable the constructor to install the equipment in the desired manner. The various industry codes and standards and laws and rules of regulating bodies should be followed where applicable.

For maximum plant personnel safety, transmission systems are employed to eliminate the piping of hydrocarbons, acids, and other hazardous or noxious materials to instruments in control rooms. Proper installation is essential in order to use fully the capabilities that are built into the instrument or transmission system.

In the installation of an instrument, the various components must be accessible for efficient maintenance, and certain of these elements must be readable for good operation. Orifices. control valves, transmitters, thermocouples, level gages, and local controllers, as well as analyzer sample points, generally should be readily accessible from grade. permanent platforms. or fixed ladders. In this manual, special consideration is given to the location, accessibility, and readability of the elements.