How you prevent boiler water corrosion?

       Prevention of corrosion:

• Oxidation – by chemically or mechanically.

• Caustic cracking – adding chemical, such as sodium nitrate (NaNO₃) or sodium sulphate (Na₂SO₄).

• Galvanic action – by using sacrificial anodes.

• Acid corrosion – by lime [Ca(OH)₂] and soda ash [Na₂CO₃] treatment and also by scavenging the oxygen.

           MgCl₂ + Ca(OH)₂ = Mg(OH)₂ + CaCl₂

          CaCl₂ + Na₂CO₃ = CaCO₃ + 2 NaCl      (these 2 are dissolved salt)

• External fire side corrosion – by maintaining the gas temp above 160°C.

      Water treatment recommendation:

a)    To prevent scale – Na₃PO₄

b)    To prevent alkalinity & minimize corrosion – NaOH & NaCO₃

c)     For conditioning sludge – sodium aluminate

d)    Remove oxygen – Na₂SO₃ / N₂H₄

e)     Reduce risk of caustic cracking – Na₂SO₄ & NaNO₃

f)      Prevent carryover of foaming – antifoam