Used 297 square feet T304 stainless steel shell and tube heat exchanger. Manufactured by Perry Products. (126) T304 Stainless steel tubes, 3/4" diameter X 12' long, rated 75 psi /FV @ 320F. Shell carbon steel 12" diameter X 12' long, rated 75 psi /FV @ 320F. T304 Stainless steel heads. Horizontal design. Expansion Joint. Shell 2-pass. Serial #B2770. National Board #2410. Built 1980.