A new part to the series, , is also in development, focusing specifically on main burner ignition criteria for gas-fired heaters.
Understanding API RP 556: Instrumentation, Control, and Protective Systems for Gas Fired Heaters
API RP 556 also applies to steam generation facilities, carbon monoxide or waste-gas steam generators, gas turbine exhaust-fired steam generators, and unfired waste heat steam generators. api rp 556 pdf
The 2nd Edition was published in April 2011 and remains the active version as of its 2024 reaffirmation. Standard Evolution:
Safety professionals use API RP 556 to establish appropriate safety integrity levels (SILs) for Safety Instrumented Functions, design interlock systems, and ensure adequate protection against hazardous events. The standard helps determine whether the complete instrumentation and control system will enable the unit to be started up, operated, and shut down satisfactorily and safely. A new part to the series, , is
API RP 556 defines several key control objectives for fired heater operation:
Always verify the revision date. API does not offer free public PDFs, so budget ~$250–350 for the document. Standard Evolution: Safety professionals use API RP 556
Internal safety auditors and external inspectors use the text as a checklist to verify that operational fired heaters are adequately instrumented. Accessing the Authorized Document
API RP 556 is being expanded into a multi-part series to provide more detailed guidance on specific aspects of fired heater safety. The is being developed under the API Committee on Refinery Equipment (CRE) Subcommittee on Instrumentation and Control Systems (SOICS).