Constant wattage heat trace cable is more commonly used for process heating and velocity flow control of heavier materials like wax, honey and other viscus material. Constant wattage can be used for freeze protection, but this is more common in commercial plants and large-scale piping projects. Constant wattage cable requires a temperature controller or it will burn itself out due to its high heat ability. Some constant wattage heat trace cable can be used in corrosive environments and up to maximum temperature ratings up to 797 degrees.