Screw Plug Immersion Heaters consist of hairpin tubular elements welded or brazed into a screw plug and provided with terminal enclosures for electrical connections. They can be screwed through a threaded opening into a tank wall or vessel. Welding or brazing depends upon the element sheath and plug material compatibility. Depending upon the customer requirement, thermo wells, thermostats or control panels can be used with these heaters to meet the objective of precise temperature control.