Used Doyle & Roth MFG. Co. Inc. approximately 240 sq ft.316L stainless steel U-Tube, shell and tube heat exchanger. 16" diameter X 7'-2" long. Carbon steel shell rated 75 PSI @ -20 to 350 degrees F. 316L stainless steel tubes and tubesheets rated 75 PSI @ -20 to 350 degrees F. Has (89) 3/4" tubes. National Board # 15411. S/N J-6564-1. Built 1991. 4" service inlets. (1) 6" and (1) 3" process inlets.