46 CFR §63.15-3

1. (a)Firing of an automatic auxiliary boiler by natural gas is prohibited unless specifically approved by the Marine Safety Center.
2. (b)Heated heavy fuel oil may be used provided the heaters are equipped with a high temperature limiting device that shuts off the heating source at a temperature below the flashpoint of the oil and is manually reset. When a thermostatically-controlled electric oil heater and a level device is used, it must meet the requirements of subpart 111.85 of this chapter.
3. (c)The fuel oil service pump and its piping system must be designed in accordance with § 56.50-65 of this subchapter. All materials must meet the requirements of subpart 56.60 of this subchapter. The use of cast iron or malleable iron is prohibited.
4. (d)The fuel oil service system (including the pump) must meet the pressure classification and design criteria found in table 1 to § 56.04-2 of this subchapter.
5. (e)When properly selected for the intended service, fuel pumps meeting the performance and test requirements of UL 343 (incorporated by reference, see § 63.05-1) meet the requirements of this section.