One used 399 Sq. Ft. Shell and Tube Heat Exchanger Type BEM18-120, Hastelloy C22 Tubes, tube sheets and bonnets with (208) 3/4" Diameter x 10' Long tubes rated 100 PSI full vacuum @ 300 F, carbon steel shell rated 100 PSI @ 300 F, 8",4",3" tubes inlet/outlet, 4" shell inlet/outlet, Mfg by Atlas, 1993. Serial# 8295, National Board# 7024.