[Code of Federal Regulations] [Title 46, Volume 2] [Revised as of October 1, 2004] From the U.S. Government Printing Office via GPO Access [CITE: 46CFR63.15-3] [Page 314] TITLE 46--SHIPPING CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PART 63_AUTOMATIC AUXILIARY BOILERS--Table of Contents Subpart 63.15_General Requirements Sec. 63.15-3 Fuel system. (a) Firing of an automatic auxiliary boiler by natural gas is prohibited unless specifically approved by the Marine Safety Center. (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 part 111, subpart 111.85 of this chapter. Note: An auxiliary boiler may be safely ignited from the cold condition using unheated diesel or light fuel oil and subsequently shifted to heated heavy fuel. (c) The fuel oil service pump and its piping system must be designed in accordance with Sec. 56.50-65 of this chapter. All materials must meet the requirements of part 56, subpart 56.60 of this chapter. The use of cast iron or malleable iron is prohibited. (d) The fuel oil service system (including the pump) must meet the pressure classification and design criteria found in Sec. 56.04-2, Table 56.04-2 of this chapter. (e) When properly selected for the intended service, fuel pumps meeting the performance and test requirements of ANSI/UL 343 meet the requirements of this section.