A PTFE lined butterfly valve protects pipelines carrying aggressive media with a continuous fluoropolymer lining – disc, seat ring and body bore are shielded against acids, alkalis and solvents. Fergo supplies PTFE lined butterfly valves in DN40 to DN300, PN10/16 and ANSI Class 150, with hand lever, pneumatic or electric actuation – many variants available from stock.
The wrong sleeve material in a PTFE lined butterfly valve rarely costs much at purchase, but it does in operation: corrosion at the seat ring, swollen seals, leaks and unplanned downtime. For water, air or neutral media, EPDM or NBR seats are usually sufficient. However, once acids, alkalis, solvents...
A PTFE lined butterfly valve protects pipelines carrying aggressive media with a continuous fluoropolymer lining – disc, seat ring and body bore are shielded against acids, alkalis and solvents. Fergo supplies PTFE lined butterfly valves in DN40 to DN300, PN10/16 and ANSI Class 150, with hand lever, pneumatic or electric actuation – many variants available from stock.
The wrong sleeve material in a PTFE lined butterfly valve rarely costs much at purchase, but it does in operation: corrosion at the seat ring, swollen seals, leaks and unplanned downtime. For water, air or neutral media, EPDM or NBR seats are usually sufficient. However, once acids, alkalis, solvents or high-purity substances are involved, elastomer seals reach their limit. This is exactly where the PTFE lining makes the difference – it forms a continuous, chemically inert barrier between the medium and the metal body. For a full overview of all butterfly valve types, visit our butterfly valves category.
What Is a PTFE Lined Butterfly Valve?
A PTFE lined butterfly valve is a valve in which all wetted parts – seat ring, disc and body bore – are covered with a continuous layer of polytetrafluoroethylene, typically at least 3 mm thick. The medium never contacts the metal. The advantage over a simple seat-ring seal: complete corrosion protection rather than only a sealed sealing surface. The construction principle separates two functions: the body made of ductile iron or stainless steel provides mechanical strength, while the PTFE lining provides chemical resistance. This allows the use of a robust, economical body material without resorting to expensive full-material exotic alloys. Soft-seated PTFE seats achieve tight shut-off according to ISO 5208 – essential wherever leakage must be prevented.
Technical Specifications at a Glance
Fergo provides PTFE lined butterfly valves in different nominal sizes, pressure ratings and material versions for precise technical selection. The key specification criteria:
- Nominal size: DN40 to DN300 (1½″ to 12″)
- Pressure rating: PN10, PN16 and ANSI Class 150
- Body style: Wafer for compact installation between two flanges, or Lug for single-flange mounting
- Body material: Ductile iron GGG40 / GGG50 or stainless steel 1.4408 – see also stainless steel butterfly valves
- Sleeve material: PTFE or PTFE with EPDM support ring
- Disc: Stainless steel CF8M (1.4408) or stainless steel with PTFE coating
- Actuation: Hand lever, gearbox, pneumatic or electric actuator, free shaft
- Temperature range: Typically –25 °C to +200 °C in continuous operation
Which Media and Applications Suit a PTFE Lined Butterfly Valve?
PTFE lined butterfly valves are designed for highly corrosive media where elastomer seals fail: acids, alkalis, solvents and many oxidising agents. Typical applications include the chemical industry, pharmaceuticals, food and beverage production and water treatment – wherever corrosion resistance and product purity are critical.
Less suitable are highly abrasive solids or slurries and continuous temperatures above the PTFE operating limit; in these cases, metal-seated butterfly valves are the better choice. To check whether your specific medium is compatible with PTFE, use our chemical resistance tool.
Standards and Connections: EN 593, EN 558, EN 1092 and ISO 5211
Metallic butterfly valves follow the European standard EN 593, which defines minimum requirements for design, materials and testing. The face-to-face length is specified by EN 558, and flange dimensions follow EN 1092-2 (PN10/PN16) or ASME B16.5 for ANSI Class 150 – so the valve fits existing flange connections without modification.
For automation, the top flange is designed to ISO 5211. This standardised interface allows direct mounting of pneumatic or electric quarter-turn actuators from various manufacturers – without custom brackets. This simplifies maintenance, spare parts management and future automation upgrades.
Manual, Pneumatic or Electric Actuation?
The actuation type depends on the application: hand lever or gearbox for manual shut-off, pneumatic actuator for fast and frequent switching cycles in process automation, electric actuator for precise remote control. The ISO 5211 interface makes every PTFE lined butterfly valve automation-ready.
- Manual: Hand lever (latching) or worm gearbox for larger nominal sizes
- Pneumatic: Double-acting or single-acting (spring-return, NC) – see pneumatic butterfly valves
- Electric: Multi-voltage 24 V / 230 V / 240 V AC/DC – see electric butterfly valves
- Free shaft: For mounting an existing or custom actuator
PTFE or PFA – Which Lining Suits Your Application?
PTFE reliably covers the broad spectrum of standard aggressive media and is the economical choice for most acids, alkalis and solvents. For particularly demanding media, higher temperatures or applications with the strictest purity requirements, a PFA lining may be the better solution – as a melt-processable fluoropolymer, PFA forms a low-porosity, continuous inner surface.
For such cases, Fergo offers PFA lined valves as a complementary range. Which approvals the respective variant meets can be found on our certifications page – different certificates are available depending on the model.
Buy PTFE Lined Butterfly Valves at Fergo
Fergo supplies PTFE lined butterfly valves to DIN and ANSI standards, many models available from stock – with fast delivery across Europe, on request also worldwide. Use the filters above to narrow by DN, PN, body, sleeve and actuation to find the right valve for your application.
Three key takeaways: the PTFE lining protects all wetted parts, the selection follows the sequence DN → PN → body style → body material → sleeve → actuation, and media compatibility can be verified in advance using the resistance tool. Configure your PTFE lined butterfly valve now or request technical advice if your medium requires individual assessment – our team has over 20 years of experience across industries from chemicals to pharmaceuticals.