Diameter 22 in; Material SSSteel; National Board Number 353; Number Of Tubes 224; Overall Length 283 in; Serial Number 501; Sq Ft 1077; 1" OD, 7/8" ID by 21 ft Long SS Tubes, Heads are Carbon Steel, Body SS, Shell Side-75 Psi at 250°F, Tube Side-75 Psi at 250°F, Shell Thickness-.1875", Head Thickness-.375", 6" Openings, On Base