Indirectly heats process fluids in either gaseous or liquid states. The fluids flow through the heated coils in the heater. The coils are immersed in a liquid bath heated by a fire tube, which is heated by a burner. The liquid bath may be a mixture of water and glycol, a salt solution, or occasionally a thermal fluid, depending upon the temperatures needed. Capacities range from 300,000 to 6 million Btu/hour.
