Electric immersion heater, just as its name implies, is the electric immersion heater for heating liquid, the main characteristics is due to the electric heater immersed in the liquid, emanating from the electric heater energy had been absorbed by the heating of the liquid, so that energy efficiency is very high, coupled with small volume, easy to control, is widely used in petroleum, chemical, metallurgy and other fields is the petrochemical industry is the ideal heat exchange equipment. There are many kinds of submerged electric heater, the most commonly used are threaded, flange type and so on.