Get current pricing for Cousins, Cousins 100 Sq Ft Sh 100 Square Foot Vertical Shell & Tube Heat Exchanger. Hastelloy B Tubes (121) 3/4 Od X 16 Bwg X 4', 3 Long. Carbon Steel Shell 12 3/4 Diam . Product Category: Process Equipment, Sub Category: Process Heat Exchangers: