ASTM D6823 Specification for Commercial Boiler Fuels with Used Lubricating Oils
5. Classification
5.1 There are four grades of burner fuel containing recycled lubricating oils covered by this specification. These grades may or may not correlate directly with similar grades in other ASTM standards. The RFC designation identifies them as recycled fuel oil, commercial boilers. The usage descriptions of each grade may not describe all the uses, but are included as general information. The four grades are described as follows:
5.1.1 Grade RFC4 - Primarily a blend of used lubricating oils and middle distillate or a reprocessed distillate product derived from used oil. It is intended for use in pressure atomizing industrial burners or commercial boilers with no pre-heating. This grade of recycled oil fuel is used in many medium capacity industrial burners and commercial boilers where ease of handling justifies the higher cost over the heavier used oil fuels.
5.1.2 Grade RFC5L - A blend of a used lubricating oil or a reprocessed product from used oil and middle distillate or residual fuel of intermediate viscosity heavier than RFC4. It is intended for use both in pressure-atomizing industrial burners and commercial boilers not requiring higher cost middle distillates and in burners and commercial boilers equipped to atomize fuel oils of higher viscosity with or without preheating. Its permissible viscosity range allows it to be pumped and atomized at relatively low-storage temperatures.
5.1.3 Grade RFC5H - A used lubricating oil and residual blend fuel, heavier than Grade RFC5L. It is intended for use in industrial burners and commercial boilers equipped with devices that atomize fuel oil of higher viscosity. Preheating may be necessary in some types of equipment for burning and in colder climates for handling.
5.1.4 Grade RFC6 - A high-viscosity used lubricating oil and fuel heavier than Grade RFC5H. It is intended for use in large industrial heaters and boilers and may require preheating in the storage tank to permit pumping. Additional preheating at the burner may be necessary to permit satisfactory atomization. The extra equipment and maintenance required to handle this fuel usually preclude its use in small installations.
