Pneumatic Fluorine-lined Butterfly Valves
DELCO Pneumatic Fluorine-lined Butterfly Valves are fully lined with PTFE/PFA to isolate the body from media. These air-actuated valves offer exceptional corrosion resistance for acid recovery systems and chemical processing plants.
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Pneumatic PTFE Lined Flanged Butterfly Valve (DN40-DN1200) - AW Series High Torque | DELCO
Size Range:DN40-DN1200
Material:Cast Iron, WCB, SS304/316 etc.
Connection Standard:GB / ANSl /JIS /DIN
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DELCO DK67-DCF Pneumatic Lined Flange Butterfly Valve - PTFE+FEP, Anti-Corrosion
Size Range: DN40-DN1200
Material:Cast Iron, WCB, SS304/316 etc.
Connection Standard: GB / ANSI / JIS /DIN
Pneumatic Fluorine-Lined Butterfly Valve: Extreme Chemical Corrosion Immunity
Engineered to handle the most destructive corrosive media in modern chemical processing, the Delco pneumatic butterfly valve fluorine-lined series encapsulates the entire wetted body and disc surface in high-density virgin fluoropolymers (PTFE, PFA, or FEP). Designed for concentrated sulfuric acid, hydrochloric acid, wet chlorine gas, and aggressive pickling liquors, these valves combine high-integrity corrosion barriers with rapid-response pneumatic actuators for critical automated isolation and emergency dumping.
Technical Merits: Fluoropolymer Sealing & Rapid Automation
Minimum 3.0mm thick virgin PTFE/PFA lining completely isolates metal ductile iron castings from liquid and vapor chemical contact across the full pH 0–14 spectrum.
Every lined body and disc is 100% non-destructively inspected with a 20,000V high-frequency spark test to guarantee zero pinholes, micro-cracks, or molding porosity.
Wide spherical disc-hub seals energized by dynamic Belleville washer springs prevent stem fugitive emissions under thermal cycling and high-frequency actuation.
Spring-Return (SR) pneumatic actuators execute complete emergency shutoff in 0.4 to 0.8 seconds upon air supply loss or hazardous gas sensor alarm triggers.
Actuators feature hard-anodized internal cylinders with external multi-coat epoxy or PTFE coatings and A4 stainless fasteners to resist aggressive ambient chemical fumes.
PFA transfer-molded designs utilize machined dovetail retaining grooves to mechanically lock the liner to the casting, preventing liner collapse under full vacuum at 150°C.
Technical Specifications Matrix
| Parameter | PTFE-Lined Wafer/Lug | PFA-Lined Split-Body | FEP-Lined Moderate Class |
|---|---|---|---|
| Nominal Size Range | DN50 – DN600 (2" – 24") | DN50 – DN400 (2" – 16") | DN50 – DN300 (2" – 12") |
| Pressure Rating | PN10 / PN16 / Class 150 (1.0 – 1.6 MPa) | PN10 / PN16 / Class 150 | PN10 / PN16 (1.0 MPa) |
| Liner Material & Thickness | Virgin PTFE (≥ 3.0 mm) | Melt-Molded PFA (≥ 3.5 mm) | FEP Fluoropolymer (≥ 3.0 mm) |
| Body Structural Shell | Ductile Iron GGG40.3 / WCB | Two-Piece Ductile Iron / CF8 | Ductile Iron GGG40 / WCB |
| Operating Temp Range | -30°C to +180°C (-22°F to 356°F) | -30°C to +200°C (-22°F to 392°F) | -30°C to +150°C (-22°F to 302°F) |
| Spark & Leak Testing | 20 kV DC Spark Test (Zero breakdown); API 598 / EN 12266-1 Rate A Bubble-Tight Leak Test | ||
| End Connection Styles | Wafer (Universal), Full Lug (ASME B16.5 / DIN EN 1092-1), or Short Flanged | ||
| Pneumatic Actuation | Double-Acting (DA) or Single-Acting Spring-Return (SR Fail-Close/Fail-Open); Air Supply 0.4 – 0.7 MPa | ||
| Automation Accessories | NAMUR Solenoid (ATEX/IECEx Ex-d), APL-410N Explosion-Proof Limit Switch, Air Filter Regulator | ||
Frequently Asked Questions: Pneumatic Fluorine-Lined Valves
Q1: What is the primary difference between PTFE and PFA lining in pneumatic butterfly valves?
PTFE is compression-sintered, offering excellent chemical inertness up to 180°C. PFA is a true melt-processable fluoropolymer that can be transfer-molded directly into complex body geometries with locking dovetail grooves. PFA offers a higher continuous temperature threshold (200°C), lower gas permeation rates, and superior vacuum stability.
Q2: How does the valve stem prevent toxic acid fumes from escaping into the atmosphere?
The disc-hub transitions feature pre-compressed spherical sealing surfaces that match the concave liner profile. Behind the liner, high-elasticity silicone or FKM energizers maintain constant live compression against the disc hub. External Belleville spring washers on the packing follower automatically take up wear, ensuring compliance with TA-Luft and ISO 15848 fugitive emission standards.
Q3: Can fluorine-lined butterfly valves handle high vacuum service?
Standard loose-fitted PTFE liners can collapse or pull away from the body casting under negative pressure. For vacuum applications, Delco supplies transfer-molded PFA lined valves where the polymer is mechanically locked into machined anchoring grooves, certified for full vacuum (-0.1 MPa) up to 150°C.
Q4: How does actuator sizing differ for lined valves compared to metal valves?
Fluorine-lined butterfly valves feature elastomer energizers behind the liner that exert continuous mechanical interference against the disc edge to guarantee bubble-tight sealing. Delco factors a 1.35x to 1.5x safety margin into pneumatic actuator torque calculations, preventing undersizing in viscous chemical or crystallization-prone processes.
Direct Factory Supply: Heavy-Duty Fluorine-Lined Butterfly Valves
Direct manufacturer supply of virgin PTFE and PFA lined butterfly valves assembled with rapid-action pneumatic actuators. 100% 20kV spark tested and hydro-tested for zero-leakage chemical plant reliability.