Used 80 Sq. Ft. SS vertical U-Tube Heat Exchanger, built by Alabama Heat Exchanger, 1996. 304-SS Shell rated 75 PSI @ 350 deg F. 316-SS Tubes rated 75 PSI @ 300 deg F. 316-SS Heads. 8" dia shell. (52) tube holes, .75" dia x 8' L. 1 Pass Shell, 2 pass tubes.