In steam producing boilers high temperatures and pressures increase the likelihood for corrosion and failure from said damage. The main culprit in this situation comes during the shutdown process, as pressure drops air enters the boiler and oxygen within the air reacts with the metal boiler causing weaknesses and pits in the metal. These small weaknesses can turn into leaks quickly requiring immediate shutdown.
To solve the problem of oxygen entering the system a nitrogen blanket can be installed. This is a system which fills the boiler system with nitrogen before dumping the pressure to eliminate air ingress, nitrogen is non-reactive in the system avoiding further pitting or corrosion. Supplying nitrogen for a blanket can come from bottled sources, liquid supplies, or through pressure swing adsorbtion.
Click here for the full article by Brad Buecker.