Uniform steam distribution to each of the coil core tubes is accomplished by proper header assembly design. The steam supply connection should be located in the center of the header, with a perforated plate type baffle located directly behind this connection. Properly sized orifices are located in each of the core tube entrances into the header.
Coils are "freeze resistant," also known as the dual-tube design. It is important to note that any steam coil can freeze when exposed to freezing temperatures without the proper drainage of the condensate. This coil design utilizes a smaller inner tube, with precisely spaced, directional, orifice type perforations. This is to help direct condensate flow to the return header.