Can titanium pumps be used to handle 32% alkaline solutions?
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This post was last edited by sunjl1981 on 2013-1-6 at 21:46. Dear friends: We have used titanium pumps to handle 32% alkaline solutions, and the surface of the impellers showed numerous small pits resulting from corrosion. I wonder if there is a problem with the quality of the pumps, and also whether titanium pumps can be used for handling 32% alkaline solutions? Please share your thoughts. ， ， -
For 32% alkaline solutions, if the temperature is not high, 304 material is sufficient; titanium pumps are generally used for handling media containing chloride ions, and they are not suitable for handling alkalis.
It can’t be used; I already missed one chance. It has been corroded
I would like to ask why it can’t be used. Could you provide a detailed explanation? We generally use stainless steel pumps to transport alkaline solutions
This post was last edited by kkav on 2010-12-4 at 17:38. I’d like to ask gently: don’t people usually look up corrosion data sheets in such cases? The corrosion resistance of titanium in alkaline environments at room temperature is generally poor when the concentration is below 20%; even if the concentration is lower, it still isn’t sufficient when dealing with alkalines at high temperatures. The degree of alkali corrosion resistance mainly depends on the ability to resist intergranular corrosion. Pages 1 through 69 of the corrosion data sheets are dedicated to electrochemical corrosion theory. What the friend on the second floor said isn’t entirely accurate either – titanium can only be used in alkaline or acidic environments at room temperature where there are chloride ions with appropriate oxidizing properties. This is closely related to the characteristics of anions, as well as the strength of the two types of polarization. It’s also related to the properties of protective films, expansion coefficients, passivation ranges, the characteristics of acid-forming elements, the reactivity of special elements, and even metallography. In reality, things seem quite complex; I still haven’t figured it all out. I hope I haven’t misled the original poster, and I hope some expert can explain this to me.
Titanium is expensive because of one thing； Secondly, titanium pumps are not suitable for transporting caustic soda; although the corrosion data sheet indicates an annual corrosion rate of around 0.05 mm (this probably refers to the situation in a soaked state), no dense protective film is formed in caustic soda.
Titanium pumps cannot be used for handling alkalis, as titanium is not resistant to alkali corrosion; stainless steel pumps can be used instead
Titanium cannot be used; for normal temperatures, a 316L stainless steel pump is sufficient. For high-temperature alkaline environments, nickel materials are the best choice.
Titanium materials are used for oxidation prevention; for alkaline solutions at lower temperatures, stainless steel is sufficient. Of course, you can also go for the luxury option of using nickel material~