The coldest circulation water flows through this air-cooler bundle. Undercooling increases the partial pressure of air, while the partial pressure of the steam drops, the overall pressure of the mixture remaining approximately constant. In this manner, the proportion by weight of steam extracted with the air is reduced to a minimumTubesThe tubes are those elements of the condenser which most heavily stressed. In conse- quence, the utmost care and attention is devoted to their fitting, method of support and fix- ing.The tubes are roller expanded into the holes of the tube plates. The tube plates separate the steam chamber and the water box. At the inlet end, the expanded tubes are flared in order to obtain favorable inlet streamline flow conditions and to prevent erosion (Fig. 1 and 2).