Why isn't steel used to make a hot water tank?

Answer 1

*It depends upon the quality of water.

Raw water is generally heated in copper vessels.

*Mild steel and other cast steelare very susceptible to chloride attacks present in the water and may leads to SCC[Stress corrosion cracking].Further it will corrode easily in this application when it comes in contacts with the air.

1.Copper is a metal that does not react with water (H2O), but the oxygen of the air will react slowly at room temperature to form a layer of copperoxide on coppermetal.

2.It is important to note that in contrast to the oxidation of iron by wet air that the layer formed by the reaction of air with copper has a protective effect against further corrosion.

3. It is a ductile metal with excellent electrical conductivity, and finds extensive use as an electrical conductor, heat conductor, as a building material, and as a component of various alloys.

4.Above all copper has a good thermal conductivity. http://www.copper.org/resources/properti...

Answer 2

steel can rust. The treatments to reduce this are frequently poisonous to humans and therefore storing water in this can cause contamination. Copper is used because it does not degrade in water