The impact of extremely high chloride ion content on stainless steel insulated tanks
Thread Content
Dear experts: I’m a tech novice and have a question I’d like to ask for your help. The company has a stainless-steel insulated heating storage tank, in which palm acidified oil products are currently stored at a temperature of 60 degrees. The moisture level was excessively high; since the water was at the bottom, after releasing a large amount of water, the chloride ion concentration in the tank was found to be as high as 2400 mg/kg. How long can storage under these conditions cause irreversible damage to the storage tank? What follow-up actions need to be taken?
It has been stored there for over half a month now, but I still can’t pick it up; I’m very worried
This post was last edited by Wang Wei2 on 2022-5-17 at 22:07. Stainless steel is vulnerable to chloride ions; especially when the pH level of the water is acidic, severe pitting corrosion can occur. In this case, anti-corrosion treatment must be applied.
For corrosion protection, polyaniline coatings are recommended as they offer good resistance to chloride ions.
Hello, thank you for the reply. It’s been over half a month since it was shipped – is it really urgent to get the goods sold? Generally, how long does it take for irreversible damage to the tank to occur in such situations?
It’s best to release it now, conduct an inspection, and then apply surface anti-corrosion treatment.
This post was last edited by chen7179 on 2022-5-18 at 17:26. Based on the data shown in the diagram, to assess corrosion resistance, titanium material should be chosen.
Generally, when constructing a new storage tank, depending on the medium to be stored, using carbon steel with an anti-corrosion coating is sufficient to solve the problem and offers the best cost-performance ratio. If the stainless steel tank is to be modified, it is sufficient to apply an anti-corrosion coating to its inner wall.
If shipment cannot be carried out in a short period of time, it is recommended to enhance the drainage system; meanwhile, deionized water can be added in small amounts multiple times to dilute the chloride ions, until their concentration drops below 50 mg/m3 as indicated above