660 Sq. Ft. Stainless Steel Horizontal Shell and Tube Heat Exchanger. SS Shell Side rated 50 PSI @ 250° F; SS Tube Side rated 75 PSI @ 200° F. (336) Tubes with 5/8†OD x 12’ long. Shell diameter -18â€. Shell-1 pass, Tubes-2 pass. Fittings: Shell (2) 8", 3/4" drain; Tubes (2) 6", (1) 3", 3/4" drain, Mfg: Struthers-Wells, S/N: E-36-C. NB #2792.