Circulation Heaters, also known as “in line heaters,” have uses in many applications. They can use steel, stainless steel, or titanium depending on the application. Lube oil and waste oil applications often use steel for circulation heaters. This is because it is fairly inexpensive compared to stainless steel counterpart. Water circulation heaters use stainless steel because of its anti-corrosive qualities. In both applications, a pump flows the liquid, such as water or glycerol, through a closed pipe circuit. The liquid is reheated as it flows through the circulation heater. A major consideration for this application is viscosity. Electric circulation heaters generate heat, making the medium less viscous. The less viscous the fluid, the easier it is to pump through a circuit of pipes.
Industrial circulation heaters come in a range of watt densities. Watt densities are specifically designed for the medium they will heat. The required wattage to heat the oil or water is highly correlated to the flow rate (in GPM).