How to Select the Right Tubes for Different Chemical Environments?

We have already discussed the impact of operating temperature on hoses and how to select the right tubes for different operating temperature. Similarly, the acid and alkali resistance of pipes is also an important indicator. How should we choose the right hose in different acid and alkali environments?

Mild Acid & Alkali Environments

◆ PVC: Moderate corrosion resistance, not heat-resistant, but low-cost and highly versatile. Suitable for general industrial applications.

◆ PU: Moderate corrosion resistance, excellent transparency, flexibility, wear resistance, and impact resistance.

◆ PA: Resistant to mild acids and alkalis but not strong acids or bases. Good wear resistance, pressure resistance, and solvent resistance. Suitable for general industrial applications.

◆ PE: Lightweight, durable, and more corrosion-resistant than PVC. Suitable for transporting mild acid and alkali media, but with limited heat resistance.

◆ PP: Higher mechanical strength, better corrosion resistance than PE, and improved heat resistance, but brittle at low temperatures. Suitable for chemical applications.

◆ NR (Natural Rubber): Excellent elasticity and wear resistance, but poor chemical resistance and moderate heat resistance. Used in general industrial applications.

◆ Silicone Hose: Moderate acid and alkali resistance, wide temperature range, and excellent biocompatibility. Suitable for food and pharmaceutical industries.

Summary: PVC and PU are suitable for general industrial use; PE and PP are more corrosion-resistant for chemical and food applications; NR and silicone hoses are best for food and medical industries.

Moderate Acid & Alkali Environments

◆ FKM (Fluoroelastomer): Excellent resistance to strong acids, high temperatures, and oil, but moderate alkali resistance.

◆ EPDM: EPDM rubber pipe has good resistance to acids and alkalis, especially bases. Excellent weather resistance and wide temperature range but not oil-resistant.

◆ ETFE: Good resistance to most strong acids and bases, with high mechanical strength. However, it may degrade in high-temperature strong alkali conditions, requiring careful selection.

Strong Acid & Alkali Environments

◆ PTFE: PTFE chemical hose has exceptional chemical stability, resistant to almost all strong acids, bases, oxidizers, reducers, and organic solvents (except molten alkali metals and fluorinated media).

◆ PFA: Chemical resistance close to PTFE but offers better flexibility and processability.

◆ FEP: Slightly lower chemical resistance than PTFE and PFA but still suitable for most environments. High transparency (over 90%) and non-toxic, odorless, and easy to process.

◆ ETFE: Suitable for chemical pipelines and coatings requiring high mechanical strength and impact resistance. Slightly less chemically resistant than PTFE/PFA but highly wear-resistant.

◆ PVDF (Polyvinylidene Fluoride): Slightly lower chemical resistance than PTFE but offers superior mechanical strength and wear resistance, making it suitable for high-pressure environments.

Summary: PTFE and PFA are the best choices for maximum chemical resistance. ETFE provides higher mechanical strength, while FKM is ideal for high-temperature acid environments but has weaker alkali resistance.

Conclusion

When selecting hoses, it is crucial to consider pH value, temperature, pressure, and the nature of the medium. For strong acid and alkali environments, PTFE, PFA, FEP, ETFE, and PVDF are the best choices to ensure chemical stability and durability. Choosing the right material improves safety and reduces maintenance costs in the transportation system.

Fokca is a professional manufacturer specializing in various pneumatic components. We offer a wide range of fittings, tubes, and china ptfe hose, available in different sizes and multiple thread types. If you need more details, please visit our Product Page.

Additionally, check out our Blog Page, where we provide in-depth articles, images, and videos to help you better understand pipe threads and pneumatic tube fittings.