Boiler Feed Water - Chemistry and Impurity Limits
The maximum recommended
- Total Dissolved Solids (TDS)
- total alkalinity
- total dissolved solids
according to ABMA - American Boiler Manufacturers Association:
Boiler Operating Pressure (psig) (bar) | Total Dissolved Solids - TDS - (ppm) | Total Alkalinity (ppm) | Total Suspended Solids (ppm) |
---|---|---|---|
0 - 50 0 - 3.5 |
2500 | 500 | |
50 - 300 3.5 - 20 |
3500 | 700 | 15 |
300 - 450 20 - 30 |
3000 | 600 | 10 |
450 - 600 30 - 40 |
2500 | 500 | 8 |
600 - 750 40 - 50 |
1000 | 200 | 3 |
750 - 900 50 - 60 |
750 | 150 | 2 |
900 - 1000 60 - 70 |
625 | 125 | 1 |
Maximum Allowable Impurities in Boiler Water
Chemical | Symbol | Maximum Concentration (ppm) |
---|---|---|
Sodium sulphite | NA2SO3 | 1.0 |
Sodium chloride | NaCl | 10.0 |
Sodium phosphate | NA3PO4 | 25.0 |
Sodium sulphate | NA2SO4 | 25.0 |
Silica oxide | SiO2 | 0.20 |
Related Topics
• Steam and Condensate
Design of steam & condensate systems with properties, capacities, sizing of pipe lines, system configuration and more.
Related Documents
ASME - International Boiler and Pressure Vessel Code
The International Boiler and Pressure Vessel Code safety rules governing design, fabrication, and inspection of boilers and pressure vessels, and nuclear power plant components during construction.
Boiler - Efficiency
Combustion gross and net calorific value.
Boiler Blowdown
Suspended solids in the feed water will remain in the boiler when steam is generated.
Boiler Blowdown Rate
Calculate boiler blowdown rate.
Boiler Capacities
Steam boilers output can be expressed in Boiler Horsepower, MBTU or in Pounds of Steam delivered per hour.
Boiler Water - Total Dissolved Solids (TDS)
Impurities from the feedwater will concentrate in the boiling water.
Cavitation
Cavitation occurs in fluid flow systems where the local static pressures are below the fluids vapor pressure.
Feed Pumps in Steam Systems - Suction Lift Head vs. Temperature
Cavitation of impellers increases with water temperatures.
Feed Water Treatment to Avoid Corrosion
Make-up water to steam boilers should be treated with oxygen scavengers to avoid serious corrosion problems.
Steam Boiler Rating vs. Feed Water Temperature
Boiler output vs. feed water temperature.
Water Supply Systems - Impurity Limits
Typiclal limits for impurities in drinking water.
Water Systems - Maximum Flow Velocities
Water velocities in pipes and tubes should not exceed certain limits.