NFPA 85, Boiler and Combustion Systems Hazards Code

Improve building fire and life safety and help ensure compliance by referencing the latest requirements for boiler and combustion systems.

NFPA^® 85, Boiler and Combustion Systems Hazards Code, is a critical resource to help minimize risks and prevent explosions and implosions in boilers, pulverizing fuel systems, and heat recovery steam generators. From design, installation, and inspection criteria to coverage of the full range of equipment and systems, the revised and expanded 2023 edition offers the most current information. 

Significant changes include:

• Addition of new requirements, expanded and clarified existing language, and defined terms
• Added requirements in Chapter 4 and in the annex that prescribe a written commissioning plan for all new and retrofitted boilers
• Updated requirements for signage and procedures, along with any necessary personal protective equipment to reduce the risk of injury, for observation ports that open into enclosures
• Introduction of an alternative to the current vent sizing where the potential leakage of the upstream valve is known and a valve-proving system is in use
• Revised definition for noncombustible material for consistency with other NFPA documents
• Changes to the safety integrity level (SIL) for single burner boilers in Chapter 5 from SIL 3 to SIL 2 to ensure that the programmable logic controller (PLC) and input/output (I/O) modules are certified by an independent organization and not the manufacturer
• New SIL requirements clarify that the burner management system logic is implemented in the safety area of the processor and not with the control system in the general-purpose area of the processor
• Expanded multiple burner boiler requirements in Chapter 6 for interlock functional tests and new annex material that outlines the intent and goals of the test
• Revised starting sequence for multiple burner boilers to specify that the trial timer begins when the individual igniter safety shutoff valve(s) is energized and not when proven open
• Change from the nomenclature leak test to the fuel gas header system tightness test to better reflect the requirement to ensure the main safety shutoff valve and upstream individual burner safety shutoff valves are not leaking. (The multiple burner boiler annex material for this test has been rewritten to better contextualize the requirements for the user.)
• Revised starting sequence for multiple burner boilers throughout Chapter 6 to reflect that overfire air is in service before the boiler is operating
• Minimum safety requirements and informational text added in Chapter 8 and its associated annex material to more accurately describe the conditions under which a turbine/ heat recovery steam generator (HRSG) system can achieve combustion turbine purge credit
• The term coal replaced with fuel throughout Chapter 9 since the specific type of raw fuel being used is not necessarily coal

2023 (NFPA8523)

2019 (9781455922703)