Shell types Heat Exchanger are classified into fixed and floating type Heat Exchangers. Fixed type Heat Exchangers are used where there are absolutely no chances for inter mixing of two fluids. In this type, the tube sheets are completely welded to the shell and acted as shell flanges. The Floating type Heat Exchangers has the advantages of removability of tube bundle and access for cleaning both inner and outer side of tubes and shell. BEU heat exchanger are shell and tube exchangers with tube bundle consisting of 'U' shaped tubes fixed by mechanical rolling to only one tube sheet. This type of heat exchangers is designed and built with removable shell and tube to allow easy maintenance.