Another problem with water in boilers is corrosion. Oxygen in the water sets up iron corrosion. Gases are driven off in to the lines which will recombine with the condensed steam to form weak but corrosive acids in the lines. The primary function of the B-G Boiler Guard treatment is to change the composition of the water so that it is no longer harmful to either the process or the equipment. How Boiler Treatment Works Untreated water with mineral salts dissolved in it comes in contact with the tube walls.
Heat is applied through the tube wall into the water causing it to evaporate or boil off.
The dissolved mineral salts are left behind on the tube. Because they are immediately insoluble in water, they drop out as a precipitate or sludge. This sludge is in turn removed from the boiler by regular blow-down. Insoluble salt formation is not the end of the B-G function, though. If the sludge is not further treated, it could drop out in the form of a heavy cake, which would be difficult to remove by blow-down.