Fluorine-Lined Control Valve

Fluorine-Lined Control Valve Product Manual (PTFE/F46/PFA Full Series)
I. Product Overview
The fluorine-lined control valve is an automated control valve designed specifically for highly corrosive media. The valve body utilizes base materials such as carbon steel, cast iron, or stainless steel, while all wetted parts (valve body, plug, seat, and internal flow passages) are manufactured using a high-pressure integral molding process with fluoroplastic linings (PTFE, F46, or PFA). The medium contacts only the fluoroplastic layer, completely isolating it from the metal substrate; this effectively resolves issues such as corrosion from strong acids and alkalis, valve body rusting, and leakage caused by perforation.
This product features a compact, single-seat, top-guided structure paired with a pneumatic diaphragm or electric intelligent actuator. It accepts standard 4-20mA analog signals to precisely regulate pipeline media flow, pressure, temperature, and liquid level. The flow passage utilizes an S-shaped streamlined design, offering low flow resistance, high control linearity, and sensitive, stable operation. It is the premier corrosion-resistant control valve capable of precise automatic control for applications involving chemicals, environmental protection, pharmaceuticals, and pickling processes.
Applicable temperature range: -29°C to 250°C (PFA up to 250°C; PTFE/F46 suitable for -29°C to 200°C).
II. Lining Material Distinctions

1. PTFE (Polytetrafluoroethylene)
   Features exceptional chemical stability, non-stick properties, and good self-lubrication; offers broad-spectrum corrosion resistance, suitable for the vast majority of conventional acidic and alkaline media; applicable temperature range: -29°C to 200°C.
2. F46 (FEP – Fluorinated Ethylene Propylene)
   Features uniform lining formation, high toughness, crack resistance, negative pressure resistance, and resistance to delamination; suitable for frequent cycling (opening/closing) and vacuum conditions; applicable temperature range: -29°C to 200°C. 3. PFA (Perfluoroalkoxy)
   A high-end anti-corrosion lining offering superior resistance to permeation, creep, and high temperatures; it is free from leaching and highly resistant to aging. With a maximum temperature rating of 250°C, it is suitable for demanding operating conditions involving high temperatures, highly corrosive media, and high-purity fine chemical processes.
   III. Structural Features

• Fully Fluoroplastic-Lined Anti-Corrosion Structure: The valve body, plug, and seat are completely encapsulated in fluoroplastic, ensuring no metal comes into contact with the process medium; this eliminates corrosion-induced perforation, rusting, and leakage.

1. Top-Guided Precision Regulation: The top-guided plug design ensures smooth, vibration-free operation, delivering high regulation accuracy and excellent linearity.
2. Zero-Leakage Bellows Seal: Employs a dual-sealing structure combining a fluoroplastic bellows with packing to completely eliminate stem leakage, making it suitable for toxic, volatile, or high-value media.

• ​​Streamlined Low-Resistance Flow Path: The unobstructed S-shaped flow path minimizes pressure drop and maximizes flow capacity, reducing the risk of crystallization or clogging.

2. Switchable Air-to-Open/Air-to-Close Action: Direct-acting and reverse-acting configurations are available to meet safety requirements for “fail-open” or “fail-closed” operation.
3. Comprehensive Automation Compatibility: Compatible with pneumatic diaphragm actuators or intelligent electric actuators; supports accessories such as positioners, solenoid valves, valve position feedback units, and emergency handwheels; integrates seamlessly with DCS remote control systems.
4. Modular Disassembly: Components such as the plug, seat, and seals can be replaced individually without removing the entire valve, simplifying maintenance and reducing costs. IV. Technical Parameters
5. Nominal Diameter: DN20–DN200
6. Pressure Rating: PN10, PN16, PN25, Class 150LB
7. Liner Material: PTFE / F46 / PFA
8. Operating Temperature: -29°C to 200°C (F4/F46); -29°C to 250°C (PFA)
9. Control Signal: 4-20mA DC standard analog signal
10. Flow Characteristics: Linear, Equal Percentage

• Leakage Class: Class IV; Class VI (soft seal, zero leakage)

2. Actuation: Pneumatic diaphragm, intelligent electric
3. Connection Type: Flanged (GB/ANSI standards)

• Sealing Structure: Fluoroplastic bellows seal (zero external leakage)
  V. Applicable Operating Conditions and Media
  ✅ Applicable Conditions

2. Fine chemicals, petrochemicals, pesticides, pharmaceuticals: Flow and pressure regulation for strong acids, strong alkalis, organic solvents, and corrosive intermediates
3. Environmental desulfurization, wastewater treatment: Automatic regulation systems for pickling wastewater, chlorine-containing sewage, and corrosive waste liquids
4. Chlor-alkali industry, electroplating industry: Precise control of highly corrosive, volatile, and toxic media
5. Regulation of media in negative-pressure vacuum lines, or media prone to crystallization, adhesion, or corrosion
6. High-temperature corrosive conditions (PFA liner option allows temperatures up to 250°C)
   ❌ Inapplicable Conditions

• Media containing large hard particles, sharp grit/sand, or causing severe erosion/abrasion (risk of scratching the fluoroplastic liner)

2. Special media such as molten alkali metals or liquid fluorine
3. Conditions exceeding material limits for pressure or temperature
   VI. Standards

• Design and Manufacturing: GB/T 4213, IEC 60534, HG/T 3704

2. Flange Standards: HG20592, ASME B16.5
   Pressure Testing Standards: GB/T13927, API598
   Explosion-proof Rating: Ex d IIC T6 (Explosion-proof version available)
   VII. Installation and Operating Instructions
   The valve must be installed vertically with the actuator facing upward; inverted or tilted installation is prohibited to prevent valve plug jamming or bellows deformation.
   Thoroughly purge the pipeline before installation; strictly prevent welding slag or particulate impurities from entering the valve to avoid scratching the fluoroplastic lining and sealing surfaces.
   During commissioning, input a 4-20mA signal to calibrate the zero point, span, and full-stroke operation, ensuring smooth regulation and precise linearity.
   For high-temperature applications, raise the temperature gradually; avoid rapid heating or cooling to prevent lining blistering, delamination, or cracking.
   For media prone to crystallization or adhesion, perform periodic full-stroke opening and closing cycles to prevent scaling or jamming that could affect regulation accuracy.
   For negative pressure applications, the F46/PFA lined version is preferred due to its superior resistance to delamination.
   VIII. Summary of Product Advantages
   The fluorine-lined control valve combines superior corrosion resistance, zero external leakage, high-precision regulation, and a wide operating temperature range (-29 to 250°C). It solves the problems faced by standard stainless steel control valves, such as inability to withstand acid/alkali corrosion and susceptibility to perforation and failure. Featuring responsive operation, stable regulation, and low maintenance requirements, it serves as a specialized core valve for automated control pipelines handling highly corrosive media in the chemical, environmental protection, and pharmaceutical industries.