Unused 3695 Sq. Ft. Horizontal Reco Industries lnconel Shell & Tube Heat Exchanger. Stainless steel shell rated 120 psi @ 550 F on the shell, and Inconel tubes rated 135 psi @ 650 F. (1815) Tubes - 3/4" dia x 11'L. Serial # N6439.30, National Board #81444, Built 1985. Previous Use: Nitric Acid - Tail Gas Heater (Spare)