Material Selection And Advantages Of Pfa Lined Flanged Butterfly Valves

For chemical and petrochemical applications, the PFA lined flanged butterfly valve provides a fully encapsulated PFA lining that isolates the metal body and disc from corrosive media. Flanged connections (PN10, PN16, 150LBS) enable secure installation. PFA lining offers lower permeability and higher temperature resistance compared to PTFE, with continuous operation from -29°C to 200°C versus PTFE's 180°C limit. The one-piece disc and shaft design eliminates leak paths while the 360° seat energizer ensures bubble-tight shut-off.

PFA Lining Advantages Over PTFE

• The pfa lined butterfly valve uses melt-processible PFA resin that forms a less permeable liner than sintered PTFE.

• Reduced permeability prevents media penetration through the liner, protecting the metal substrate from corrosion.

• PFA provides a firmer polymer structure that reduces cold flow and maintains dimensional stability under pressure cycling.

• The pfa butterfly valve offers enhanced resistance to permeation from small molecules like chlorine gas and organic solvents.

• PTFE liners, being compression-moulded from sintered chips, contain microscopic pathways that allow media migration over time.

• The pfa lined butterfly valve eliminates this vulnerability through its injection-moulded, void-free construction.

Technical Specifications

Sealing and Safety Design

• The pfa butterfly valves incorporate a 360° seat energizer that ensures bi-directional bubble-tight shut-off.

• The live-loaded stem sealing system with V-ring packing self-adjusts to maintain integrity under thermal cycling, reducing fugitive emissions.

• The one-piece disc and shaft design prevents leakage pathways where the disc meets the stem.

• This construction eliminates the need for separate seals that could fail during operation.

• All PFA-lined components undergo high-voltage spark testing to verify liner integrity without voids.

Chemical Service Applications

• Strong acids: sulfuric, hydrochloric, and nitric acid handling where PFA's chemical inertness prevents attack.

• Chlor-alkali processing: chlorine gas and brine solutions benefit from PFA's permeation resistance.

• Semiconductor manufacturing: ultrapure water and aggressive etchants require PFA's purity and corrosion resistance.

• High-temperature processes: PFA-lined valves handle temperatures up to 200°C for demanding reactions.

Installation and Operation

1. Install between flanges with proper gasket seating (PTFE, PFA, or FEP).

2. Tighten flange bolts evenly to specified torque.

3. Pneumatic/electric actuator rotates disc 90° for open/close.

4. Full port design provides minimal pressure drop.

5. Live-loaded stem seal maintains integrity over valve life.

Maintenance and Reliability

• The pfa lined butterfly valve requires minimal maintenance due to the self-lubricating PFA surface that prevents media adhesion.

• The 360° seat energizer compensates for wear, maintaining sealing force throughout the valve's service life.

• The one-piece construction eliminates disc-to-stem seals that typically require replacement in other designs.

Engineering Value for Process Safety

The pfa lined butterfly valve reduces fugitive emissions through its live-loaded stem sealing system. The PFA lining provides superior permeation resistance, preventing hazardous media escape through the liner. The flanged connection eliminates threaded joints that could leak. ISO 5211 actuator mounting simplifies automation.

Proper valve selection ensures reliable corrosion-resistant service. Select lining material based on temperature requirements and verify compatibility with process fluids.

1. Select liner material: PTFE for -29°C to 180°C, PFA for -29°C to 200°C, FEP for -29°C to 150°C.

2. Verify flange rating matches process pressure (PN10, PN16, or 150LBS).

3. Choose gasket material compatible with process fluids and temperature.

4. Select actuator type based on automation and fail-safe requirements.

These measures ensure reliable chemical service. Properly specified PFA lined flanged butterfly valves deliver corrosion resistance and bubble-tight performance in chemical and petrochemical applications.

FVF PFA Lined Flanged Type Butterfly Valve With Extension Bar

• FVF lined butterfly valve features a state-of-the-art design that provides excellent shutoff protection (bubble-tight shutoff) and high Cv values with exceptionally long service life. The resilient seated butterfly valve is available in a variety of materials including PTFE, PFA, Stainless Steel and special alloys to fit a wide range of customer requirements.
• FVF lined butterfly valves are available with Wafer style or Lug style 150# ANSI flange connections. They can be equipped with a manual lever or can be actuated with electric or pneumatic actuators. A full range of accessory items are available including limit switches, solenoid valves, positioners and manual override devices.
• FVF lined butterfly valves bi-directional flow is possible at maxmium operating pressure. Since the valve port corresponds to the piping diameter, a high flow capacity is guaranteed.It features ease of maintenance, repeatable on-off, long life durability.
• It is commonly used in the power generation, brewing, water and food industries and suitable for both gaseous and liquid service. Typically applied in chemical/petrochemical process, food and beverage, and pulp and paper etc.