Consultation on 32% alkali storage tank leakage
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Hello everyone, one of the 32 alkali tanks in our company leaked. Upon inspection, many sand holes were found, so the bottom plate was replaced. However, it started leaking again shortly after the replacement, and inspections revealed sand holes once more. It’s unclear what caused it; if it were alkali embrittlement, cracks should be present, but no cracks were found. We are using carbon steel, and the temperature is around 40 degrees, so we would like to ask for advice. What material is used for the 32 alkali tanks at Dajia Company? How are they performing? What is the temperature of the alkali solution? Have there been any leaks, and what were the causes of those leaks and the measures taken to address them?
Great material; move it to the Static Devices section for more discussions
32% alkaline solution? I also built two alkali tanks before, and one of them worked fine. Another case was caused by the owner adding coils privately out of fear of freezing, which led to temperatures exceeding the normal level. Personally, I think it’s still the temperature that causes it. Let’s take a look at what other sea friends think; I’m here to learn* as well.
What is the critical temperature? ? ?
According to HG20581-2020, when the temperature of the NaOH solution exceeds 46 degrees and reaches the boiling point, carbon steel and low-alloy steel welded chemical containers are prone to alkali stress corrosion cracking.
Is it for the material itself, or for the areas in the weld where there are restraint stresses?
Stress corrosion is likely a problem related to the material itself and its environment, especially at welds
I know that the welds in alkali pipelines are subjected to heat treatment to reduce stress. For tanks of this size, how can welding stress be reduced? ? ?
Proper layout, control of welding processes, hammering after welding