Flanged & Screw Plug Tubular Immersion Heaters Industrial Electric Immersion Heaters - Flange Mount and Screw Plug Mount Product Overview This product line covers tubular sheathed immersion heaters used to heat liquids, fluid directly inside tanks, vessels, and pipelines. Each heater consists of a bundle of hairpin-bent tubular heating elements attached to a mounting base, which can be a round flange, screw plug (threaded boss), or a customized shape such as square or triang