The flange immersion heater adopts stainless steel tube coat, modified magnesium oxide powder, high-performance nickel-chromium electrothermal alloy wire and other materials. This series of tubular water heater can be widely used in heating water, oil, air, nitrate solution, acid solution, alkali solution and low-melting point metals(aluminum, zinc, tin, Babbitt alloy). It has good heating efficiency, uniform temperature, high temperature resistance, corrosion resistance and good safety performance.