NFPA 85 Boiler and Combustion Systems Hazards Code applies to the full range of large boilers and systems, including Large boilers, including atmospheric fluidized bed boilers with a minimum fuel input rating of 12.5 million Btu/hr (3.6 MW), Stoker operations, Pulverized fuel systems, Fired or unfired steam generators used to recover heat from combustion turbines, Single Burner Boilers, with more other additional systems.