Abstract: Two alternative flow patterns through a heat exchanger core are provided by a tank (20) including a baffle (40) dividing the tank into first and second chambers (42 and 44). A first port (50) is provided in the baffle (40) to establish communication between the chambers (42 and 44). A second port (52) is provided to the second chamber (44). The tank (20) further incudes plugs (62 and 64) that are receivable in the tank (20) for alternatively closing the first port (50) while opening the second port (52), and opening the second port (52) while closing the first port (50).

Abstract: A shell and tube heat exchanger for exchanging heat between a shell side fluid and a tube side fluid has a longitudinally extending shell, a longitudinally extending tube bundle and one or more baffles positioned within the shell for directing the shell side fluid to flow across the tube bundle. One or more valves is also provided within the shell of the heat exchanger. Each valve is operable between a first position and a second position and co-operates with a baffle for adjusting the flow of shell side fluid through the shell side of the exchanger. Each of the valves is controlled by an external actuator.