water circulation electric heater is a kind of energy-saving equipment that pre-heats the material, which is installed before the material equipment to realize the direct heating of the material, so that it can be heated in the high temperature cycle, and finally achieve the purpose of saving energy. It is widely used in the pre-heating of heavy oil, asphalt, clean oil and other fuel oil. The pipe heater is composed of two parts: body and control system. The heating element is made of stainless steel pipe as protection sleeve, high temperature resistance alloy wire, crystalline magnesium oxide powder, formed by compression process. The control part is composed of advanced digital circuit, integrated circuit trigger, high reverse voltage thyristor and other adjustable temperature measurement and constant temperature system to ensure the normal operation of the electric heater.