Refer to the following table for recommended boiler water quality for Total Dissolved Solids (TDS), Alkalinity and Hardness.
Proper Feedwater Treatment is an absolute necessity!
Unless your boiler receives water of proper quality, the boiler's life will be needlessly shortened. A steam plant's water supply may originate from rivers, ponds, under ground wells, etc. Each water supply source requires a specific analysis. Depending upon this analysis, various pretreatment methods may be employed to prepare makeup water for your
boiler feedwater system.
General Information on Water Treatment
Suspended solids represent the undissolved matter in water, including dirt, silt, biological growth, vegetation, and insoluble organic matter.
minerals dissolve in water, ions are formed. The sum of all minerals or ions in the water in the total dissolved solids or the TDS.
Iron can be soluble or insoluble. Insoluble iron can clog valves and strainers and can cause excessive sludge build up in low lying areas
of a water system. It also leads to boiler deposits that can cause tube failure. Soluble iron can interfere in many processes, such as printing or the dying of cloth. In domestic water systems, porcelain fixtures can be stained by as little as 0.25 ppm of iron.
Hardness is the measure of calcium and magnesium content as calcium carbonate equivalents. Water Hardness is the primary source of scale in boiler equipment.
Silica in boiler feedwater can also cause hard dense scale with a high resistance to heat transfer.
Alkalinity is a
measure of the capacity of water to neutralize strong acid. In natural waters, the capacity is attributable to bases, such as bicarbonates, carbonates, and hydroxides; as well as silicates, borates, ammonia, phosphates, and organic bases. These bases, especially bicarbonates
and carbonates, break down to form carbon dioxide in steam, which is a major factor in the corrosion of condensate lines. Alkalinity also contributes to foaming and carryover in boilers.