PTFE is known for its broad chemical resistance and is used with many aggressive media. Nevertheless, compatibility must be established for the particular substance and operating conditions.
Media considered in the source article
- Acids. Identify the acid, its concentration and the operating temperature before selecting the assembly.
- Alkalis. Check the exact composition and service conditions, including any oxidising constituents.
- Organic solvents and oils. The original article discusses acetone, ethanol, methanol, benzene and oils. Compatibility must be confirmed for the actual fluid or mixture.
- Gases. The article considers hydrogen, oxygen, nitrogen, air and argon. The suitability of the complete assembly must be reviewed for the intended gas service.
How to use compatibility information
A general compatibility table is a screening aid, not a product approval. The chemical identity, concentration, temperature, pressure and exposure conditions all need to be stated.
The source contains an illustrative chemical-resistance table and several specific exceptions. These have not been reproduced as verified operating guidance. Request compatibility information for the proposed assembly before selecting it.
Look beyond the tube
The PTFE tube is only one part of the assembly. Fittings, seals and other exposed components must also be suitable for the conveyed medium and the surrounding environment.
Where the application requires it, arrange an appropriate compatibility assessment or testing under representative conditions. Send the fluid specification and operating conditions to LLETALL for a product-specific review.