Used 75 Sq Ft Allyn American, Inc Vertical 316L Stainless Steel Shell and Tube Heat Exchanger, rated 120 PSI @ 350F on the shell, 45 PSI/FV @ 293 F on the tube side. (85) 1.5" dia tubes. 20" dia x 6'9" OAL. National Board # 137, Serial # 1723, Built 2001.