A baffle in a heat exchanger having two sections hingedly connected so as to facilitate removal of the tube bundle. A top section of the baffle defines a plurality of apertures through which tubes of a removable bundle extend and has edges one of which is connected to an edge of the bottom section of the baffle in a manner which permits the bottom section to rotate relative to the top section when the heat exchanger tube bundle is being removed. When the novel features of this invention are incorporated in a heat exchanger, removal of the tube bundle is facilitated.