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  • 1.  Material to be used in HF vapour service

    Posted 04-19-2023 17:37

    Hi All,

    I am just looking for material recommendations that can be used in Hydrofluoric Acid vapour service. Any guidance would be appreciated.

    Regards,

    Rahat Hussain



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    Rahat Hussain
    Lead Static Equipment Engineer
    Incitec Pivot Limited
    Annandale QLD
    0417276148
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  • 2.  RE: Material to be used in HF vapour service
    Best Answer

    Posted 04-20-2023 12:20

    HF is very nasty stuff, so be careful.
    Without more details of temperatures etc., you may wish to look at:
    MTI publication MS-4 - Hydrogen Fluoride and Hydrofluoric Acid (covers a wide range of temperatures/concentrations, metallics and non-metallics)
    NACE Publication 5A171-2007, Materials for Storing and Handling Commercial Grades of Aqueous Hydrofluoric Acid and Anhydrous Hydrogen Fluoride  (not sure if this has been officially withdrawn, but is available at the AMPP store. Covers essentially ambient temperature acid.)
    The Nickel Institute has 2 free publications on HF where you may find relevant information, go to https://nickelinstitute.org/library/  and using the search engine, put it the publication numbers - 10074 and 443.  



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    Nickel Institute
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  • 3.  RE: Material to be used in HF vapour service

    Posted 04-23-2023 22:05
    Edited by Rahat Hussain 04-23-2023 22:07

    Thank you all for your input and special thanks to Gay Coates for precise response and reference to Nickel Institute. 

    Regards,
    ------------------------------
    Rahat Hussain
    Lead Static Equipment Engineer
    Incitec Pivot Limited
    QLD, Australia
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  • 4.  RE: Material to be used in HF vapour service

    Posted 04-21-2023 05:57

    One of the most corrosion resistant materials for strong acids is High Silicon cast iron. It has a very low dissolution rate in acids and can be safely used upto 200 ⁰C.
    Let me know if this is useful 



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  • 5.  RE: Material to be used in HF vapour service

    Posted 04-21-2023 09:25

    Rahat,

    Another resource that may be useful is

    Herbert S. Jennings, Corrosion by Hydrogen Fluoride and Hydrofluoric Acid, Corrosion: Environments and Industries, Vol 13C, ASM Handbook, Edited By Stephen D. Cramer, Bernard S. Covino, Jr., ASM International, 2006, p 690–703, https://doi.org/10.31399/asm.hb.v13c.a0004182

    Scott



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    Scott Henry
    Senior Content Engineer
    ASM International
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  • 6.  RE: Material to be used in HF vapour service

    Posted 04-21-2023 07:49

    Hi Rahat, 

    Are you looking for metal or polymer based materials? 

    The following materials have been proven to be compatible with hydrofluoric acid vapors to some extent:, Teflon (PTFE), Kynar (PVDF), Hastelloy C-276, Monel 400, Graphite (maybe) if not too hot. 



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    University of Virginia
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  • 7.  RE: Material to be used in HF vapour service

    Posted 04-21-2023 13:40

    As others have said, HF is quite nasty.  The literature states: "Hydrogen fluoride is an extremely hazardous material, in the liquid or vapour form."   Corrosiveness of HF is highly dependent upon water content, concentration and temperature, each of which can determine best material compatibility   As I'm sure you know, the safety data sheet should be carefully reviewed before using HF in any form. For example, do a Google on "Guidelines for the Safe Use of Hydrofluoric Acid."  NOTE: A material that should not be used with HF is high silicon cast iron. For example, the Total Materia database under the topic "High Silicon Cast Iron" states: "When silicon levels exceed 14.2% high silicon cast irons exhibit excellent resistance to H2SO4, HNO3, HCl, CH3COOH, and most other mineral and organic acids and corrosives. These materials display good resistance in oxidizing and reducing environments and are not appreciably affected by concentration or temperature. Exceptions to universal resistance are hydrofluoric acid (HF), ..."   As others have said, the Nickel Institute has several excellent references regarding HF; one example is "Alloy selection for service in hydrogen fluoride, hydrofluoric acid and fluorine." Also, there is an online document; "Materials of Construction Guideline for Anhydrous Hydrogen Fluoride."  Fluorinated polymers may also be useful, depending on temperature, among other factors.



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