A fluid connector for providing an inlet/outlet connection to a connecting grid of a heat exchanger is disclosed in which the connector has a tubular body formed with an integral outwardly directed flange by means of which a fluid tight connection to the connecting grid can be achieved. The flange may be sealed relative to an aperture in a plate of the connecting grid. Alternatively, the aperture may be provided with a structural ring and the flange sealed relative to the structural ring for adapting the aperture to the size and/or position of the flange. A set of structural rings may be provided for use of the connecting grid with different connectors. The structural ring may allow the connector to be detached without disassembling the connecting grid. The aperture may be closed by a blanking disc.