Which anti-corrosion coating is the best for sulfuric acid pipelines?
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This post was last edited by sunjl1981 on 2013-1-6 at 19:52. The concentration of the waste sulfuric acid in our factory is around 80%~90%. Previously, the waste sulfuric acid pipelines were lined with rubber, but after about 2 years the rubber gradually peeled off and caused blockages in the pipelines. We are now planning to apply an anti-corrosion coating again; our plan is to use PO lining, as the saltwater pipelines are also lined with PO and the results have been good. However, we are not sure what the effect of using PO lining for sulfuric acid pipelines will be. # ， ， &
I’ve seen them; they seem to be lined with tetrafluoroethylene. This post was last edited by sdtclfg on 2009-4-7 11:14]
It is recommended to use steel-lined PTFE or PVC+FRP, which yields good results and virtually eliminates pipeline blockages
Check the corrosion data manual; at such high concentrations of sulfuric acid, it seems that carbon steel can be used directly within a certain temperature range. I can’t remember; I don’t have it on hand. Could someone help look it up?
98% sulfuric acid tanks of ours are made of carbon steel, with a thickness of 10 mm. Currently, the minimum thickness at the top is around 9.3 or 9.4 mm, due to moisture. However, the pipes surrounding the tanks are likely made of stainless steel. Tanks used for 78% sulfuric acid have a fiberglass lining, and the towers also have PTFE linings. Last edited by limingshuguang on 2009-4-11 at 11:25
Strengthening the PVC pipe will do; carbon steel pipes won’t work. This post was last edited by Duplicate names are not allowed on 2009-4-9 20:29 ]
The friend upstairs is being too absolute. Today I specifically checked the corrosion data manual; concentrations below 65% are not acceptable. The acid concentration mentioned by the original poster is fine below 65 degrees, and it should be even better if it is treated with chlorine and then dried – the appropriate value is likely around 25 degrees. Of course, generally no manufacturers use carbon steel pipes in dilute sulfuric acid media after drying; I think the main concern is issues with controlling the process parameters!
75% to 85% can be achieved by wrapping fiberglass around PVC pipes； Over 85% of them require heating due to their high crystallization temperature in northern regions, and carbon steel is sufficient for this purpose.
Experience: 93% of PDFE-lined
It’s best to use ones with a PTFE lining, as they are resistant to high temperatures and corrosion. However, the lining must be installed properly, especially the quality of the welds has to be excellent (the welds between the flanges and the pipes should have rounded edges), and care should also be taken during grinding.
We are steel-lined PTFE! :lol
In reality, no matter whether PTFE lining, PTFE-coated materials, PE plastic lining, or rubber-lined pipes are used, the key factor is quality; if the quality is guaranteed, it’s acceptable to use options with lower costs.
Steel-lined PTFE is the best option; our company has been using it for five or six years now. As long as the quality is ensured, although the initial investment is high, it’s still a cost-effective choice in the long run