The lined butterfly valve features a full PTFE (F4), FEP (F46), or PFA lining on both the body and disc, providing exceptional corrosion resistance against strong acids, alkalis, solvents, and oxidizing agents . With a compact wafer or lug design and 90° lever or gear operation, this valve delivers reliable sealing and long service life in aggressive chemical environments. Available in sizes from DN50 to DN600, pressure ratings PN10-PN16, and temperature ranges from -20°C to 180°C . It is widely used in chemical processing, pharmaceutical manufacturing, hydrometallurgy, and environmental protection applications.
The lined butterfly valve is a corrosion-resistant industrial valve designed specifically for handling highly aggressive media. The valve body and disc are fully lined with fluoroplastics such as PTFE, FEP, or PFA, completely isolating the metal substrate from the process fluid . This construction effectively prevents chemical attack on the valve body while maintaining excellent sealing performance. The valve uses a centerline disc design that rotates 90° to open or close, providing quick operation with low torque requirements .
Lined butterfly valves are widely used as cost-effective alternatives to expensive alloy valves in severe corrosive service conditions, offering superior durability and reliability.
1. Full Fluoroplastic Lining
Complete PTFE/FEP/PFA lining on body and disc surfaces
Isolates metal components from corrosive media
Prevents corrosion and contamination
2. Exceptional Corrosion Resistance
Suitable for strong acids (sulfuric, hydrochloric, nitric, hydrofluoric)
Resistant to strong alkalis, organic solvents, and oxidizing agents
Compatible with aggressive chemicals including aqua regia
3. Reliable Sealing Performance
Soft PTFE seat provides bubble-tight shut-off
Meets ISO 5208 Class VI leakage standards
Bidirectional sealing capability
4. Compact & Lightweight Design
Wafer or lug connection for space-saving installation
Low operating torque for easy manual or automated operation
90° quarter-turn for fast open/close action
5. Wide Material Selection
Multiple lining materials available for different temperature requirements
Various actuation options: handle lever, worm gear, electric, pneumatic
| Parameter | Details |
|---|---|
| Model Series | D71F / D371F / D671F / D971F |
| Size Range | DN50 – DN600 (NPS 2″ – 24″) |
| Pressure Rating | PN10 – PN16 / Class 150 |
| Connection Type | Wafer / Lug / Flanged |
| Operation | Lever handle, worm gear, electric actuator, pneumatic actuator |
| Temperature Range | PTFE: -20°C ~ 180°C / PFA: -20°C ~ 200°C |
| Component | Standard Material | Optional Materials |
|---|---|---|
| Body | Cast Iron, Ductile Iron | Cast Steel, Stainless Steel (304/316) |
| Lining | PTFE (F4) | FEP (F46), PFA, PCTFE |
| Disc | Stainless Steel + PTFE fully lined | Stainless Steel + PFA lined, Duplex + PTFE |
| Stem | Stainless Steel (2Cr13, 304) | 316 Stainless Steel, Monel |
| Seat | PTFE | Reinforced PTFE, PFA |
| O-Ring / Packing | FKM (Viton) | EPDM, PTFE |
Strong Acids: Sulfuric acid, hydrochloric acid, nitric acid, hydrofluoric acid, phosphoric acid
Strong Alkalis: Sodium hydroxide, potassium hydroxide
Organic Solvents: Acetone, methanol, toluene, various organic compounds
Oxidizing Agents: Chlorine, hydrogen peroxide, hypochlorite
Other: Aqua regia, salt solutions, corrosive gases
Chemical Processing: Reaction vessel feed lines, acid transfer systems, solvent handling
Pharmaceutical Manufacturing: API production, corrosive fluid control, CIP systems
Hydrometallurgy: Ore leaching circuits, electrolyte circulation
Environmental Protection: Wastewater treatment, flue gas desulfurization (FGD), acid neutralization
Electroplating Industry: Plating bath circulation, rinse water systems
Chlor-Alkali Industry: Chlorine handling, brine systems
| Actuator Type | Description |
|---|---|
| Lever Handle | Standard for DN50-DN150, manual 90° operation with position lock |
| Worm Gear | For DN200 and above or high torque applications, self-locking design |
| Electric Actuator | Voltage: AC220V/110V/380V, DC24V; with manual override; explosion-proof available (Ex dⅡBT4) |
| Pneumatic Actuator | Double-acting or spring-return (fail-safe); air pressure 0.4-0.7MPa; optional positioner, solenoid valve, limit switches |
Installation Guidelines
Thoroughly clean pipelines before installation to remove debris
Verify flow direction arrow matches actual media flow
Install valve in upright position on horizontal pipelines whenever possible
Ensure flange bolts are tightened evenly in a diagonal pattern
For actuated valves, allow adequate clearance for maintenance access
Maintenance Recommendations
Perform spark testing on lining layer to detect any damage
Inspect lining for cracking or peeling during regular maintenance cycles
Replace seat and O-ring during scheduled overhauls
Check stem packing for leakage and re-tighten if necessary
Custom configurations are available based on specific service conditions:
High-temperature service: PFA lining for up to 200°C
Vacuum service: Heavy-duty lining with enhanced adhesion
Sanitary applications: FDA-compliant PTFE lining for food/pharmaceutical use
Explosive environments: Explosion-proof electric or pneumatic actuators (Ex dⅡBT4/CT6)
Special connections: ANSI, DIN, JIS flange standards available
For custom requirements or technical assistance, please contact us with your detailed operating conditions.
