Polyethylene and Steel Sodium Hypochlorite storage tanks

[mech51]

I am currently working on a project where I have inspected the liners of approximately 30 indoor sodium hypochlorite (SH) storage tanks used for water treatment. I have found a series of liner degradation problems ranging from blistering to flaking. Does anyone have knowledge of recommending or using a coating system to repair liners in steel tanks to resist 12% SH?

 

[RChang]

If it is a demin tank would the concentration of the SH should be much lower? You are probably initially mixing 12-15% SH along with 98% sulfuric acid to demineralized the water irregardless your biggest problem is that you final product demin water is very aggressive towards many types of coatings specially epoxies and polyester. This type of tank usually are rubber or ebonite lined but unfortunately this material are difficult to repair and test for holidays. You may want to try something like polyurea ($$$$$ very expensive) or maybe something like coal tar or the new generation of water based asphaltic emulsions with require less surface prep and less expensive.

Good luck

Rick C

 

[riewies]

Materials I know that are chemically resistant to Sodium Hypochlorite (NaCIO) are PTFE and ECTFE. They are expensive but relativly easy to apply. It appears to be a liner failure.