| Water and Demineralized Water | Generally Suitable | Ambient to moderate temperatures; clean or mildly contaminated water. | Low friction, good corrosion resistance, and low water absorption. | Hot water service can accelerate creep and seat wear; pressure and temperature derating may apply. | Suitable for general water isolation when the valve pressure-temperature rating is adequate. |
| Dilute and Concentrated Acids | Often Suitable | Many inorganic and organic acids at temperatures within the liner rating. | PTFE is highly resistant to many corrosive acids and does not rely on a protective oxide layer. | Strong oxidizing acids, high temperature, concentration changes, and impurities can alter compatibility. | Confirm the exact acid concentration, temperature, pressure, and exposure time using a chemical compatibility review. |
| Alkalis and Caustic Solutions | Generally Suitable | Most aqueous alkaline services within the recommended operating envelope. | Very good resistance to sodium hydroxide, potassium hydroxide, and many alkaline cleaning fluids. | High temperature may increase liner deformation; abrasive crystals or deposits may damage sealing surfaces. | Check concentration, operating temperature, seat stress, and the risk of solids accumulating around the disc. |
| Chlorine-Containing Chemicals | Conditionally Suitable | Selected wet chlorine or hypochlorite services at controlled temperature and concentration. | PTFE offers strong resistance to many aqueous halogenated chemicals. | Dry chlorine, strong oxidizing conditions, elevated temperature, and permeation can create significant design risks. | Verify whether the service is wet or dry and review the complete valve, stem, disc, and elastomer material combination. |
| Organic Solvents | Case-by-Case | Many solvents are acceptable at moderate temperature, but compatibility is chemical-specific. | PTFE has low swelling and good resistance to a wide range of hydrocarbons and solvents. | Some solvents can permeate PTFE, affect nearby elastomers, or create fugitive-emission concerns. | Check solvent type, vapor pressure, temperature, permeability, and the valve’s emissions requirements. |
| Oils, Fuels, and Hydrocarbons | Usually Suitable | Liquid hydrocarbon service within the pressure, temperature, and fire-safety requirements. | Low friction and broad chemical resistance to many petroleum-based fluids. | PTFE is not inherently fire-safe; permeation, rapid gas decompression, and elastomer compatibility require review. | For combustible service, specify an appropriate fire-tested design and compatible secondary sealing materials. |
| Steam and Hot Condensate | Usually Not Preferred | Only limited low-temperature or intermittent steam service if specifically approved by the valve design. | PTFE retains useful chemical resistance, but chemical resistance alone does not ensure steam suitability. | High temperature, creep, deformation, thermal cycling, and pressure-temperature derating can shorten service life. | Use a steam-rated seat and valve design; do not select a standard PTFE-lined butterfly valve solely from chemical compatibility data. |
| Compressed Air and Inert Gas | Conditionally Suitable | Clean, dry air or inert gas within the valve’s gas-pressure rating. | Low friction and low moisture absorption can support reliable operation. | Gas permeation, rapid decompression, adiabatic heating, and seat leakage may be important at high pressure. | Confirm gas-service approval, pressure class, decompression resistance, and required leakage rate. |
| High-Purity and Pharmaceutical Fluids | Suitable with Hygienic Design | Clean liquids and chemicals where the PTFE grade and surface finish meet process requirements. | Low reactivity, low absorption, and good cleanability. | Standard industrial butterfly valves may have dead spaces, unsuitable lubricants, or non-compliant elastomers. | Specify sanitary construction, surface finish, clean-in-place requirements, extractables limits, and documentation. |
| Abrasive Slurries and Suspensions | Limited Suitability | Low-solids or mildly abrasive slurries at moderate flow velocity. | PTFE can resist chemical attack from the liquid carrier. | Particles can erode the liner, scratch sealing surfaces, and increase operating torque. | For high-solids or highly abrasive service, consider a dedicated slurry valve and verify particle size and velocity. |
| Dry Powder and Granular Solids | Generally Unsuitable | Only specially engineered applications with controlled particle loading. | PTFE may reduce friction in certain low-load applications. | Particles can become trapped at the seat, cause abrasion, prevent tight shutoff, and increase torque. | Choose a valve designed specifically for dry solids, powder flow, and the required sealing duty. |