The term oil fuel unit means the equipment used for the preparation of oil fuel for delivery to an oil fired boiler, the equipment used for the preparation of heated oil fuel for delivery to an internal combustion engine, and any oil fuel pressure pump, filter, and heater that deals with oil at a pressure of more than 1.8 kilograms per square centimeter (25 p.s.i.) gauge.
[CGD 74-127, 41 FR 3843, Jan. 26, 1976]