Heat exchanger with U-tubes provided with an anti-fly-off support device

In a heat exchanger such as a nuclear plant steam generator, the U-tubes are arranged in a bundle of parallel series, and are maintained at their intermediate part by anti-vibration bars which are linked by the means of connection pins. In order to prevent the fly-off of the ensemble (anti-vibration bars and connection pins), some of the anti-vibration bars are hung in notches in such a way that no fastening bow is necessary, thus avoiding thermal expansion problems