Tank Internal Coating

[khanvessel]

Hi

I have a utility water tank,the hypochlorite package linked to this tank will produce O2 via the chemical reactions with organics in the water. There is no O2 scavenger feed. Tank material is A-516 -70

In this case, does the tank required some lining/coating to prevent corossion.

Thanks

 

[SMF1964]

Remember that sodium hypochlorite solutions also contain a small amount of sodium hydroxide to keep the pH up and the hypochlorite in solution (instead of outgassing). Add to this the chlorides in the hypochlorite it's pretty safe to say that you're going to get corrosion of the tank. I'm not so sure that the oxygen generation is a significant contribution to the aggressiveness of the environment. If the tank is vented, the system has already got all the oxygen it needs.

An internal lining or coating system is advised. I'm not too familiar on cathodic protection systems, so maybe that would work as well - someone with better knowledge will have to answer that.

 

[mshimko]

I recommend coating the inside of the tank, dependant somewhat in the size and configuration (if its not large enough and assessible for grit blasting, I may reconsider).

Cathodic protection will protect submerged areas of the tank IF the system is properly configured and there is minimal internal obstructions. If there are lots of stiffeners, swash bulkheads, etc, cathodic protection becomes difficult to properly configure. Plus, CP will do nothing for the tank areas above the water line, even though these areas are still likely wet. Hence, my strong recommendation for coating.