SS are significantly more resistant to oxidation by water and biocides than other material . This results in longer life time for water tanks.
An internal and external coating is not required for SS, nor is cathodic protection. This reduces system cost and makes stainless steels more compatible with the environment.
Due to their very high passive film stability, SS are basically inert in waters. Leaching of alloying elements (Cr and Ni) is within safe limits. As a result, they provide a better quality of drinking water.
The duplex stainless steels are much more resistant to erosion-corrosion than carbon steel, particularly if sand particles are present.
As SS is resistant to crevice corrosion, cavitation and wear in pure and polluted waters as well as in atmosphere (even polluted), they are cost-effective for long-term use and do not cause environmental pollution.
SS is 100% recyclable and a part of their initial cost may be recoverable when they are recycled. Thus, it doesn't harm the environment and saves a lot on the carbon print that we are leaving on our earth, due to the use of plastic.
Stainless steel components can provide 100 years of service due to their excellent corrosion resistance and ductility at all services temperature. Though SS tank might cost you more at first but proves to be cost-efficient in the long run.
With high corrosion resistance and easy welding, water leaks can be drastically reduced, probably from 25% down to less than 5% which leads to cost savings. All no other basic maintenance that you might need for plastic tanks.
Lower friction compared to cement lined carbon steel pipes or corroded carbon steel, results in less loss of water pressure along the pipeline. This decreases the internal diameter of the pipe and saves capital cost.
SS, particularly the duplex materials, have high mechanical properties. This allows a reduction in the wall thickness of the pipe (without any required corrosion allowance) and results in investment cost savings.