Can plastic-lined steel withstand hydrofluoric acid?

In response to your question, when using steel-lined plastic as a material for storing or transporting mixed solutions of hydrofluoric acid and other chemicals, it is necessary to consider the chemical resistance and other physical properties of the plastic lining. 1. **Steel-lined PE (polyethylene)** – Polyethylene exhibits good chemical resistance to most acids, but its resistance to hydrofluoric acid is usually insufficient, especially at higher concentrations. Prolonged exposure may cause damage to the material. 2. **Steel-lined PP (Polypropylene)** – Polypropylene generally has higher chemical resistance than polyethylene, and it offers good resistance to various acids and bases. However, hydrofluoric acid remains a challenge, especially at higher temperatures and pressures, as the properties of polypropylene may degrade. 3. **Steel-lined PO (polyolefins; it is assumed to refer to general polyolefins such as polyolefin rubber)** – Polyolefin materials generally exhibit good corrosion resistance against many chemicals. However, its performance may also be limited when faced with highly corrosive chemicals such as hydrofluoric acid. In summary, these three materials may exhibit a certain level of resistance to low-concentration hydrofluoric acid (such as below 10%) and other chemicals mentioned, but their chemical resistance is affected by increasing concentrations of hydrofluoric acid as well as changes in temperature or pressure. In practical applications, it is recommended to conduct thorough chemical compatibility tests or consult the material supplier/manufacturer to determine the most suitable material choice. Especially in environments containing hydrofluoric acid, more specialized acid-resistant materials such as PVDF (polyvinylidene fluoride) may need to be considered. .

For your operating conditions, you’ll probably have to consider lining it with fluoroplastic

Since the medium’s turbidity is not high and the pressure is low, it’s sufficient to simply use acid- and alkali-resistant plastic pipes

When hydrofluoric acid is involved, materials lined with various fluoroplastics are usually the better choice; feel free to contact us if needed

When these media are mixed together, the corrosion is very severe; it’s best to use PTFE lining directly

It is recommended to use the isostatic pressing process, imported PTFE material, major supplier: victory:

Among the plastic-lined materials such as steel lined with PE (polyethylene), PP (polypropylene), and PO (polyolefin), steel lined with PP is more suitable for environments containing 10% hydrofluoric acid and 20% hydrochloric acid. Polypropylene exhibits good chemical resistance to both hydrofluoric acid and hydrochloric acid. However, for fluorocarbon compounds, it is necessary to further confirm the specific types and concentrations of these fluorocarbons, as certain types may be corrosive to polypropylene. Polyethylene (PE) has good acid resistance, but its solvent resistance is somewhat inferior to that of polypropylene, making it possibly unsuitable for environments containing fluorocarbons. The specific type of polyolefin (PO) is not specified, and its chemical stability may also vary depending on the specific material type. In summary, steel-lined PP (polypropylene) is recommended as a relatively safe choice, but the final decision should take into account the combined effects of all chemical components, and specific chemical compatibility tests are advised. At the same time, all structures should take into account operating temperature and pressure conditions during design. .

The pressure here is very high; it’s best to use molded PTFE, as ordinary steel-lined PTFE can be easily penetrated. If possible, use compressed air on this side and create a vacuum on the other side to reduce pressure and prevent splashing.