PFA Lined Valves: Near-Universal Chemical Resistance

A PFA valve combines the mechanical strength of a metal body with the chemical resistance of a fluoropolymer lining. Perfluoroalkoxy (PFA) is applied as a thick, seamless layer over the entire wetted surface of the ductile iron or cast steel housing. As a result, no metal ever contacts the medium. The lining resists concentrated acids, alkalis, halogens, solvents and oxidising agents — media that would corrode even stainless steel within days.

Fergo supplies PFA lined valves from two Flowserve programmes. The Atomac brand covers ball valves, check valves (ARV2, ARK2), Y-strainers (ASF) and sight glasses, while the Durco brand delivers PFA lined plug valves in DIN and ANSI/ASME designs. The nominal sizes reach up to DN300. Flange drilling follows EN 1092-1 or ASME B16.5 Class 150, and face-to-face lengths follow EN 558-1. A conductive PFA-L variant additionally dissipates electrostatic charges in ATEX zones.

PFA lined valves serve the chemical and petrochemical industry, pharmaceutical production, semiconductor fabrication, chlor-alkali plants, pigment and dye production, plating lines and any process where product purity or corrosion protection is critical. Where a soft-seated design in metal is sufficient, a PTFE lined butterfly valve can be the more economical alternative. For high-purity or dosing lines, PFA remains the reference material.

Subcategories: PFA Lined Valves by Function

01 PFA Lined Ball Valves

The PFA lined ball valves form the core of the range. A ductile iron GGG40.3 body carries a full PFA lining, and the ball itself is PFA-encapsulated. Flange connections follow DIN EN 1092-1 or ASME B16.5 Class 150 in a wide range of nominal sizes. Actuator mounting follows ISO 5211, so pneumatic and electric automation is straightforward. Conductive PFA-L versions are available for ATEX zones with flammable solvents.

02 PFA Durco Plug Valves

The PFA Durco plug valves — the T4E family — carry a full PFA lining in the body and a PFA-encapsulated tapered plug. This design withstands abrasive, viscous and crystallising media that would clog ball or butterfly valves. DIN (PN16) and ANSI Class 150/300 versions cover DN15 to DN300. TA-Luft-compliant stem sealing is standard.

03 PFA Lined Check Valves (ARV2, ARK2)

The PFA lined check valves prevent backflow in aggressive media. The ARV2 works as a lift check valve with a PFA-encapsulated plug on a vertical stem, while the ARK2 uses a hinged flap design. Both series carry a ductile iron GGG40.3 body with full PFA lining and flange drilling to EN 1092-1 or ASME B16.5. They install directly upstream of pumps, dosing lines and reactor feeds.

04 PFA Lined Y-Strainer (ASF)

The PFA lined Y-strainer — the ASF series — protects downstream ball, plug, check and control valves from particles. Body and cover are PFA lined, and the exchangeable basket combines a PTFE structure with an ETFE mesh at approximately 300 µm. This ensures that the entire filtration path remains chemically resistant. Flanges follow DIN EN 1092-1 PN16 and ASME B16.5 Class 150.

05 PFA Lined Sight Glass

The PFA lined sight glass makes the medium visible without breaking the corrosion barrier. A ductile iron GGG40.3 body carries a full PFA lining, and the viewing disc is made of borosilicate glass to DIN 7080. This design allows visual monitoring of colour, turbidity, flow direction and gas bubbles in acid, alkali and solvent lines. It complements the standard sight glass range for less aggressive media.

Materials in Detail: Specifying the Right PFA Lined Valve

Body and Lining Materials

1. Ductile Iron GGG40.3 / EN-GJS-400-18-LT with PFA Lining

Application: standard body of the Atomac ball, check, strainer and sight glass series for aggressive chemicals in DN15 to DN300
Temperature: −20 °C to +200 °C
Advantages: high toughness of the ductile iron housing, seamless PFA lining without weld seams, near-universal resistance to acids, alkalis and solvents
Limitations: lining sensitive to mechanical impact during installation, limited for abrasive slurries

2. Cast Steel (WCB) with PFA Lining

Application: higher pressure and temperature ratings on selected Durco plug valves and larger flanged designs
Temperature: −20 °C to +200 °C · ASME Class 150 and Class 300
Advantages: greater mechanical strength than ductile iron, suitable for ASME Class 300, proven in refineries and petrochemical plants
Limitations: higher material cost, longer lead time on larger sizes

3. Conductive PFA-L Lining (ATEX)

Application: flammable solvents, explosive atmospheres, dry powders and any process where electrostatic charge build-up is a hazard
Temperature: −20 °C to +200 °C
Advantages: the carbon-filled PFA-L layer safely dissipates static charges to earth while retaining full chemical resistance, ATEX-compliant
Limitations: dark colouration prevents visual lining inspection; special order with surcharge

Wetted Internals

1. PFA-Encapsulated Ball, Plug, Disc or Stem

Application: all wetted internals of the Atomac ball, Durco plug and ARV2/ARK2 check valves
Temperature: −20 °C to +200 °C
Advantages: no metal contact with the medium, smooth non-stick surface prevents crystallisation and product build-up, high purity for pharmaceutical and semiconductor duty
Limitations: sensitive to elemental fluorine and molten alkali metals

2. PTFE Body Gasket

Application: sealing between body halves on all Atomac and Durco valves
Temperature: −20 °C to +200 °C
Advantages: near-universal chemical resistance, FDA-compliant, forms a hermetic seal at the parting plane
Limitations: cold flow under sustained load; replace on every disassembly

3. Borosilicate Glass Disc (DIN 7080) — Sight Glass

Application: viewing disc of the PFA lined sight glass for visual media monitoring
Temperature: up to +200 °C
Advantages: low thermal expansion, high resistance to thermal shock and chemical attack, excellent optical clarity
Limitations: not resistant to hydrofluoric acid and hot concentrated alkalis

4. PTFE / ETFE Filter Basket — Strainer

Application: exchangeable basket of the ASF Y-strainer at approximately 300 µm mesh
Temperature: up to +200 °C
Advantages: PTFE frame with ETFE mesh keeps the whole filtration path fluoropolymer, wash-cleanable and reusable
Limitations: mechanical stability lower than a stainless steel basket; not suitable for coarse abrasive solids

Fergo PFA lined valves comply with the Pressure Equipment Directive 2014/68/EU and carry the CE mark. Flange drilling follows DIN EN 1092-1 or ASME B16.5 Class 150, complemented by Class 300 for selected Durco plug valves. Face-to-face lengths follow EN 558-1, and actuator mounting follows ISO 5211. Conductive PFA-L versions are certified to the ATEX Directive 2014/34/EU for use in explosive atmospheres, and the PFA material itself is FDA-compliant for food and pharmaceutical duty.

Inspection documents to EN 10204 — type 2.2 works certificate or type 3.1 inspection certificate — are supplied on request. Selected series additionally carry TA-Luft approval for emission-relevant service. A full overview of all certificates is published on the Fergo certificate page. The technical background of the Atomac and Durco programmes is documented directly by the manufacturer Flowserve. Please verify chemical compatibility with your medium beforehand using the Fergo resistance check.

Fergo holds more than 25,000 industrial valves in stock, including a dedicated stock programme for Flowserve Atomac ball, check, strainer and sight glass series as well as Durco PFA plug valves. Standard sizes ship the same working day, so delivery follows within two to seven working days. Automation with pneumatic or electric actuators is carried out in-house.

Fergo ships across Europe — including the United Kingdom, the Nordic countries and all other EU member states. Smaller valves travel by parcel service, whereas large-bore flanged valves and consolidated shipments go by forwarding agent. You will find shipping costs, payment options and express terms on the shipping and payment terms page. For ASME Class 300 designs, conductive PFA-L variants, extended nominal sizes or 3.1 material certificates, please contact us through the customised solutions section.

PFA Lined Valves for Aggressive Chemical Media

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