Used 791 sq. ft. Atlas shell and tube heat exchanger, Hastelloy C276 tubes, tube sheets and bonnets, carbon steel shell, with (412) 3/4" diameter x 10' long tubes rated 100 PSI/full vacuum @ 320 F, shell rated 100 PSI/full vacuum @ 320 F, 10", (2) 4" tubes inlet/outlet, (2) 6" shell inlet/outlet, serial# 10029, National Board# 8534, new 1998.