Corrosion of water treatment pipelines and valves
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Dear colleagues, the pipes and valves in my workplace’s water treatment section often leak. The cause of these leaks is usually corrosion that thins out the metal surfaces. The fluid involved is treated acidic wastewater; the solution in the acid tanks consists of 40% hydrochloric acid, which is diluted before being poured into mixing tanks. After mixing and clarification, this acidic wastewater is combined with other types of wastewater, and the resulting mixture causes severe corrosion to the subsequent pipes and valves. Since there is no online monitoring system for pH levels in this process, it is not possible to automatically control the amount of acid added; instead, pH test strips must be used for testing and adjustment. Due to severe corrosion, valves and pipelines need to be inspected and replaced frequently on site, which is very troublesome. The original material used was polytetrafluoroethylene; however, due to the low temperatures in the north, they were changed to carbon steel combined with PTFE pipelines, which improved the situation slightly. But the material of the valves remained unchanged, still being ordinary carbon steel. I hope experts can discuss this in depth to find some effective solutions. Thank you
What’s the temperature? I can recommend tetrafluoride spraying for you.
The temperature is around 50 degrees Celsius; the problem is that there are still particulate substances in the wastewater
Spend the money on wear-resistant and corrosion-resistant ceramic valves instead
Carbon steel is definitely not suitable. What kind of valve is it? What is the caliber?
Tetrafluoride is okay, QQ2328276632
I don’t have any money. Are there any ways to achieve big things with little money? lol
Both gate valves and globe valves are available, with diameters ranging from DN50 to DN250
Do not use globe valves when there are particulates; use gate valves instead. I don’t know what level of corrosivity the medium has; has stainless steel been used? Butterfly valves can be considered; they are cost-effective, wear-resistant, and corrosion-resistant. Fluorinated linings cannot be used even if there are particles, as it will scratch the surface
When PH is high, it’s around 4.5. But using a butterfly valve at the pump outlet doesn’t seem very appropriate :(
This post was last edited by Wang Genrong on 2016-1-20 at 11:16; stainless steel is used. Butterfly valves can be used in areas where the pressure is not high. Another option is to use a V-type ball valve, specifically designed for applications with solid particles.