Can 316L tubing be used in a 5% dilute hydrochloric acid medium?
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Question: The internal components of our cation exchanger (such as the water inlet and intermediate drain) are made of 316L material, and acidic water or dilute hydrochloric acid at a concentration of 5% is used during operation (regeneration). Similarly, can the external pipes of the exchanger also be made of 316L stainless steel? (Currently, plastic-steel composite pipes are being used.) Thank you! ! !
It can be used; however, steel-plastic composite pipes are much cheaper and still meet the requirements.
It is not resistant to hydrochloric acid, as the chloride ions in hydrochloric acid react chemically with the nickel in 316; the reaction proceeds slowly, but problems will still arise over time. If it is to be used in the chemical industry, it might be worth considering materials such as plastic linings; you can check the chemical engineering design manuals, as they mention this.
Could you tell me which factory you work for? Can we accommodate visitors? Thank you! 1!
Austenitic stainless steels such as 316L cannot be used with hydrochloric acid of any concentration, as severe intergranular corrosion will occur.
It’s better not to use it; it’s fine for a short period of time, but you need to think ahead!
It is not suitable for use in this situation.
It must not be used under any circumstances; our factory uses rubber-lined pipes exclusively
316L stainless steel pipes should be used for at most 2 years; it is better to use PVC or ABS pipes
Hydrochloric acid has a strong reducing property, and stainless steel finds it difficult to passivate in hydrochloric acid; as a result, it cannot resist corrosion by this acid. Therefore, stainless steel is generally not used in hydrochloric acid media. However, when the hydrochloric acid concentration is very low and the temperature is low, high-nickel and molybdenum-containing high-grade Cr-Ni-Mo austenitic stainless steels, such as 00Cr20Ni25Mo4.5Cu, 0Cr23Ni28Mo3Cu3Ti, 00Cr20Ni18Mo6CuN, 00Cr24Ni22Mo7Mn3CuN, etc., exhibit considerable corrosion resistance. Among industrial-grade nickel-based alloys, 0Ni65Mo28Fe5V (Hastelloy B) and 00Ni70Mo28 (Hastelloy B-2) exhibit the best resistance to pure hydrochloric acid. The latter is better among them. It should be noted that if hydrochloric acid contains oxidizing agents, such as oxygen or ions of Fe3+ and Cu2+, it will accelerate corrosion. Table for hydrochloric acid medium --01 Effect of Fe³+ ion concentration on the corrosion of 0Ni65Mo28Fe5V alloy in 10% hydrochloric acid. Fe³+ concentration: ppm; Medium temperature: 26ºC – Corrosion rate: mm/a; Medium temperature: 66ºC – Corrosion rate: mm/a; Medium temperature: 102ºC (boiling point) – Corrosion rate: mm/a. 0: 0.033; 0.21; 0.22. 75: ---; ---; 1.28. 100: 0.071; 0.28; ---. 500: ---; ---; 6.63. 1000: 0.37; 1.33; 12.45. 5000: 1.32; ---; ---. 00Cr16Ni57Mo16Fe6W4 alloy (Hastelloy C-276) and 00Cr16Ni65Mo16Ti alloy (Hastelloy C-4) exhibit good corrosion resistance in hydrochloric acid at temperatures below about 82ºC ； The former is more corrosion-resistant than the latter. However, the corrosion of these two alloys is also affected by oxygen and oxidizing agents, although the impact of oxidizing agents is less severe due to the higher chromium content in the alloys.
It’s better not to use it; opt for the most suitable material. In fact, 316 becomes very fragile in dilute acids, so we use fiberglass reinforced plastic
At room temperature, polyolefin pipes can be used; if there is a temperature involved, polyolefin composite pipes can be utilized. (But choose one that is not prone to delamination.) Hydrochloric acid is an anaerobic acid with weak oxidizing properties; it does not react with polyolefins, nor does it cause electrochemical corrosion or anything similar. http://bbs.hcbbs.com/thread-423019-2-3.html Here, the ammonium sulfate mother liquor is transported using composite pipes on floors 22–24. The concentration of sulfuric acid is 3–5%, and the temperature is around 60 degrees. For reference.
It is absolutely not permissible to use 316; even the best austenitic stainless steels such as 310 are not suitable, as the welded areas will quickly start leaking due to intergranular corrosion. Spending so much money only for a short lifespan. You might as well take a look at our pipe – it’s the only one of its kind in the country right now! The only one in the world! Stainless steel plastic composite pipes with heat fusion joining should be your best choice! The pipes produced by our company are extremely useful for certain special applications! For example, in applications such as chemical injection pipelines with particularly high corrosivity and petrochemical pipelines, this solution completely eliminates the many problems that some companies face when using metal or plastic pipelines! This pipe material is the preferred choice for shooting venues at the Olympics. The outer layer of this pipe is made of 304 stainless steel, while the inner layer is made of polypropylene plastic. The connection is achieved through a patented heat fusion method, and all threaded connections and other components are lined with plastic to ensure that no metal comes into contact with the pharmaceutical substances. The outer stainless steel layer serves to withstand pressure, provide shielding, and enhance aesthetics. Friends who are interested are welcome to ask me for information and samples! My phone number is 13793212317, Mr. Liu Xiang
It is recommended not to use 316L pipes, as they are prone to pitting caused by Cl ions. There are no issues in the short term, but problems will arise later on. However, if the quantity used is small, 316L pipes can be used temporarily.
316L pipes cannot be used; our factory uses PVC pipes for hydrochloric acid pipelines, and they have been in use for over two years now. No leaks to date.
It can last for at most a year or two; if it needs to be replaced, the cost will have to be taken into consideration
Dilute hydrochloric acid ionizes to release some CL-, which reacts with nickel in stainless steel, damaging its surface layer and causing corrosion of the stainless steel. It is recommended to use PP or PE pipes, as they can fully meet the process requirements and are also convenient for installation, maintenance, and technical upgrades.
For corrosion resistance, it is best to use a PVC-lined interior; 316L is not reliable for long-term corrosion protection, unless it is an alloy steel such as Inconel 600 or Inconel 625.
Lining of the acid liquid pipes for ion exchanger regeneration; 316 material is used for the middle section, but it’s not possible to line that section.
I think chloride ions are highly corrosive to stainless steel; especially for 304 and 316, it’s better to use other materials