Abstract: An expansion tank and water box device for a heat exchanger with a nest of parallel tubes, such as a radiator of a motor vehicle, in which the water box housed inside the expansion tank is maintained by the assembly of the tank with the hollowed plate through which extend the ends of the tubes. Ribs are interposed between the water box and the expansion tank. Said ribs depend, for instance, from the expansion tank.

Abstract: A flexible liner, e.g. of rubber, for a manifold or apertured plate having collared apertures is disclosed, the manifold or apertured plate being part of a header tank of a heat exchanger having a bank of tubes, such as an automobile radiator. The liner has holes rimmed with sleeves corresponding to the collared apertures of the manifold or apertured plate. The sleeves are squeezed between their associated tubes and collar to effect fluidtightness around the tubes. To prevent stress developed in the sleeves being transmitted to the rest of the liner, a zone of reduced section surrounds each hole and preferably is of similar contour and coaxial therewith. The zones of reduced section are preferably grooves opening onto the side of the liner remote from the side from which the sleeves project.