When a customer needed a circulation heater to warm varying mixtures of nitrogen and hydrogen gas at differing temperatures, St. Louis-based Indeeco answered the call.

The circulation heater has a low watt density to keep the element’s sheath temperature below the autoignition point of the gases. The heater was constructed with an extra high limit thermocouple (mounted on the heater’s flange) in addition to the standard high limit thermocouple (mounted on the element’s sheath). According to Indeeco, the design provided benefits such as high limit protection from low flow and outside heat. In addition, an extended terminal box provided lower temperature to the terminal box, allowing for smaller gauge line wires.