Used 665 Sq Ft Doyle and Roth 304 Horizontal Stainless Steel Shell and Tube Heat Exchanger. (320). 75"OD x 10'L tubes rated 232 psig @ 355 F. FV @ 350F. Approximately 48" OAH x 165" OAL. Weight 5,789 lbs. Serial #S2765-4. National board #21565. Built 2015. Last use Oxidation Air Economizer.