Tubular heat exchangers consist of a casing, a head flanged to the casing and a tube bundle made up of 16 x 1 (mmxmm) tubes forming a U and expanded on the tube plate. This type of simple construction, with a removable tube bundle, allows easy cleaning of the casing during maintenance. Therefore, the fluid most susceptible to fouling should be circulated through this circuit (inlet and outlet from the casing). One of the main advantages of this type of heat exchanger is the low pressure drop in both circuits. The removable tube bundle feature also allows for easy repair or replacement.