Used 2444 Sq. Ft. Horizontal Missouri Boiler & Tank Company 304L Stainless Steel Shell & Tube Heat Exchanger. Shell rated 75 psi @ 475 F on the shell, and tubes rated 125 psi @ 475 F. Serial # H-5232, National Board #3125, Built 1971. Previous Use: Nitric Acid - Cooler Condenser, Stage 1 (Used in line - No Heads)