Used 41 sq ft C276 alloy shell and tube heat exchanger. Manufactured by RAS Process Equipment. 13 1/2" OD x 143 5/8" lenghth. SA106 Shell rated 150 psi @400F. (18).75"OD C276 tubes rated 150 psi @400F. National Board #899. Serial #981466403. Built 1998. Previous use: Pyradine preheater.