Subheading 841610: Furnaces; Furnace Burners, for Liquid Fuel
Subheading 841620: Furnaces; Furnace Burners, for Pulverized Solid Fuel or Gas, … etc.
Subheading 841630: Furnace Accessories; Mechanical Stokers, Mechanical Grates, M … etc.
Subheading 841690: Furnaces; Parts of Furnace Burners, for Liquid Fuel, Pulveriz … etc.