101.What is the function of De-aerator? What is the operating pressure?

De-aerator helps in removing dissolved O2 in the condensate thereby preventing possible corrosion inside the pipelines. Normally it is maintained at Positive pressure sufficient to maintain NPSH for BFP at all loads. Normally, for 210 Mw plant,the Dearator will be maintained at 1.5--3.5 bars.