(under subclass 497) Subject matter wherein the heater includes means for rigidly attaching the heater to a liquid container or tank.
SEE OR SEARCH CLASS
219, Electrical Heating,
526, for means for attaching housing or casing to an external device; subclasses 536+ for heater unit attachment means for heater housings in general; and subclasses 542+ for significant heating unit structure adapted for use with the heating device under the class definition and including significant resistive element attaching, securing, or insulation means.
338, Electrical Resistors,
228+, for casing extending through plate; and subclasses 315+ for resistance devices combined with mounting or supporting means.
