Used 6300 Sq. Ft. Weldon Incorporated 316 SS Vertical Heat Exchanger. 44" diameter x 26' long. (967) 1" diameter 316 SS tubes rated 25 psi @ 400 F. Carbon steel shell rated 120 psi @ 400 F. Serial # 3639-K, NB# 4274. Model # 1ST44-120. Built 1987. Drawing on file.