Corrosion
(i)by water:
physical configuration of the system
hardness of water, salts, chlorides, and dissolved gases such as oxygen, carbon
dioxide, and sulphur dioxide.
Presence of suspended solids in water
Flow rate of water
Presence of bacteria
Temperature of water
(ii) by steam:
the boiler feed water contains oxygen , it enter in the boiler, and then flashed from the boiler with steam in the steam line. It also enter the steam line when air enters in it.
Condensate pH is low due to carbonic acid. When bicarbonates break down in the boiler, CO2 produced which in turn form carbonic acid in steam.
(iii) by soil:
soil corrosion is a geological hazard that effect buried structures, pipelines, tanks and other objects that are in direct contact with the soil.
Factors that influence soil corrosion are aeration, porosity , moisture, electrical resistivity, soil pH level, dissolved salts contents, chloride contents and soil texture.
If water retention is more corrosion is more.
If aeration is more corrosion is less.
If dissolved salts more, conductivity is more and corrosion is more.