46 CFR §111.85-1

1. (a)An operating thermostat.
2. (b)Heating elements that have no electrical contact with the oil.
3. (c)A high temperature limiting device that:
   1. (1)Opens all conductors to the heater;
   2. (2)Is manually reset; and
   3. (3)Actuates at a temperature below the flashpoint of the oil.
4. (d)Either—
   1. (1)A low-fluid-level device that opens all conductors to the heater if the operating level drops below the manufacturer's recommended minimum safe level; or
   2. (2)A flow device that opens all conductors to the heater if there is inadequate flow.