A radiant-convective style heater is the most well known and commonly used direct fired heater. These heaters utilize a bare tube radiant zone in combination with a convection section. Vertical cylindrical, A-frame, and cabin style are the most common configurations. Sigma Thermal offers both API 560 and non-API direct fired heater designs in all of these configurations, as well as custom configurations.

Coil configurations and metalurgy are selected based on each customers’ process requirments. Sigma Thermal has extensive experience in process coil design for multi-phase fluids, viscous hydrocarbons, suspended solids, and various gaseous mixtures.