A fired jacketed steam kettle may be installed if it is: Constructed and stamped in accordance with the ASME Code, Section I, IV, or VIII, Division 1; and Registered with the National Board. A gas-fired jacketed steam kettle may be constructed in accordance with the ASME Code, Section VIII, Division 1, provided that: Welded joints having contact with products of combustion are Type No. 1 of Table UW-12; The minimum thickness of a part subject to pressure is, for: Carbon steel, 1/4 inch, or Stainless steel or nonferrous pressure parts, as specified in the ASME Code, Section VIII, Division 1, Subsection C; A part having contact with products of combustion is, for: Carbon steel, pressure vessel quality, and Austenitic stainless steel, either extra-low carbon or stabilized grade; Structural grade carbon steel is not used for any pressure part; The operating pressure of the jacket does not exceed 50 PSI; A vessel constructed in accordance with this regulation: Is inspected by an authorized inspector, and Is not marked with the UM symbol; Steam or water is not withdrawn from the jacket for use external to the vessel; The capacity of the safety valve in pounds of steam per hour is at least equal to the BTU rating of the burner divided by 1,000; and The jacket has: A pressure gage, A water gage glass, A separate connection, fitted with a check valve and stop valve, for adding water to the jacket while the vessel is not under pressure, An automatic gas valve controlled by pressure or temperature to maintain the steam pressure in the jacket below the safety valve setting, A low water cutoff to stop the flow of fuel to the burner if the water in the jacket drops below the lowest permissible water level as established by the manufacturer, and A safety pilot control to stop the flow of fuel to both the main burner and the pilot burner in case of pilot flame failure.