11 Industrial ovens used for drying, curing, drum warming, pre-heating, tempering, and annealing and for general purpose industrial uses; Furnaces, combustion furnaces, and structural parts therefor; Heat treatment equipment, namely, heating installations, heating elements, heating furnaces, and electrical induction heating apparatus for heating metal workpieces; Heat treatment equipment, namely, pipe heating tape, electrical heating tapes, electric heating filaments, and electric heating cables; Heat treatment equipment, namely, heating apparatus for furnaces; Heat treatment equipment, namely, heating pads, electric, not for medical purposes; Heat treatment equipment, namely, heating units for industrial purposes; Heat treatment equipment, namely, heating units for industrial purposes, namely, drying, curing, drum warming, pre-heating, tempering, and annealing metals, and pre- and post-weld heat treatment of tubes, pipes, and pipework; Heat treatment equipment, namely, heating elements for industrial purposes, namely, drying, curing, drum warming, pre-heating, tempering, and annealing metals, and pre- and post-weld heat treatment of tubes, pipes, and pipework