Used 880 Sq Ft. U-Tube Heat Exchanger. Mfg by Energy Exchanger 1987. Carbon steel Shell (SA-516) rated 150 PSI @ 500 deg F; Carbon Steel Tubes (SA-214) rated 150 PSI @ 500 deg F. Carbon Steel Heads (SA-515). Shell - 23.25" dia. x 17'11" L ; (142) Tubes - 3/4" dia. Flanged Nozzles: (1) 10", (2) 8", (2) 3", (2) 3/4". Type AJU. S/N: X-2916, NB# 1257.