PHOSPHATE 12D is a phosphate formula with a high P205 value. It is designed to react with calcium salts in boiler feed water to form calcium phosphate that is an easily conditioned sludge. PHOSPHATE 12D should be fed, under normal circumstances, to maintain an excess phosphate value of 10 – 50 ppm in the boiler water. Proper control of boiler water excess phosphate is quite important to obtain maximum results. It is undesirable to maintain excesses higher than 50 ppm and or lower than 10 ppm. To permit complete reaction between PHOSPHATE 12D and the calcium it is important that hydroxide alkalinity’s in the boiler water be maintained at a minimum of 300 – 450 ppm at all times. PHOSPHATE 12D can be fed to boilers by means of a chemical pump drawing solution from a chemical mixing tank and delivering direct to the boiler drum. In smaller plants PHOSPHATE 12D can be fed quite satisfactorily by means of by-pass chemical feeders installed on the boiler feed-line, on the discharge side of the boiler pump.