: The document addresses primary measuring instruments, actuators, control systems, alarms, and protective functions (shutdown systems). Key Components of the Standard
Understanding API RP 556: A Guide to Fired Heater Instrumentation and Control api rp 556 pdf
: This RP does not cover oil-fired or combination-fired heaters, water tube boilers (covered by NFPA 85), or specialty equipment like CO boilers and pyrolysis furnaces. api rp 556 pdf
The standard is organized to cover every stage of heater instrumentation: api rp 556 pdf