Even with good deaerating heater operation, sufficient dissolved oxygen can remain infeedwater to damage the boiler system. Lowlevels of dissolved oxygen are critical to highpressure (high temperature) systems. Oxygen in water produces pitting which is particularl severe because of its localised nature. Economisers and feedwater heaters areM especially susceptible to oxygen attack.While CorTrol OS5601 can effectively beused in low-pressure boilers systems, it wasdeveloped as an oxygen scavenger for higher pressure applications where boiler water solids are a major concern.