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Industriearmaturen Butterfly Valves

Butterfly Valves in Stainless Steel & GGG40 — Buy Online

Butterfly valves in wafer, lug or double-eccentric design, seat ring in EPDM, NBR, Viton or PTFE, DN25 to DN1200, PN6 to PN16, manual, pneumatic or electric.

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Butterfly Valves
  • Flanged shut-off butterfly valve for gas AK211G

    Flanged shut-off butterfly valve for gas AK211G

    Sizes: DN25 – DN600

    Flange connection: PN10, PN16

    Case material: GGG40 + epoxy 120 µm GJS400

    Flap: GJS400, CF8M (1.4408)

    Operations: Electric, Pneumatic double-acting & single-acting, Hand lever, Gearbox

  • Drinking Water Butterfly Valve Type AK210W

    Drinking Water Butterfly Valve Type AK210W

    Operations: Electric motor, Pneumatic double-acting, Pneumatic single-acting, Hand lever, Mounting flange (ISO 5211), Gearbox with handwheel

    Sizes: DN25, DN32, DN40, DN50, DN65, DN80, DN100, DN125, DN150, DN200, DN250, DN300

    Face-to-face: DIN EN 558-1 Reihe 20

    Flap: CF8M (1.4408)

    Pressure range: PN10, PN16

  • Stainless steel butterfly valve AK203

    Stainless steel butterfly valve AK203

    Nennweite: DN50 – DN300

    Flange connection: PN10, PN16, ANSI 150

    Case material: Stainless steel (1.4408)

    Flap seal: EPDM

    Operations: Electric, pneumatic double-acting & single-acting, hand lever, gearbox

  • Flanged shut-off butterfly valve for drinking water, type AK211W

    Flanged shut-off butterfly valve for drinking water, type AK211W

    Sizes: DN25 – DN300

    Flange connection: PN10, PN16

    Case material: GJS400 GGG40 + epoxy 120 µm, RAL5015

    Flap seal: EPDM

    Operations: Electric, Pneumatic double-acting & single-acting, Hand lever, Gearbox

  • PTFE Butterfly Valve Type AK130

    PTFE Butterfly Valve Type AK130

    Nennweite: DN50 – DN300

    Flange connection: PN10, PN16, ANSI 150

    Case material: EN-GSJ-500-7 (GGG50) Späroguss

    Flap seal: PTFE

    Operations: Electric, Pneumatic double-acting & single-acting, Hand lever, Gearbox

  • Stainless steel butterfly valve, type AK202

    Stainless steel butterfly valve, type AK202

    Nominal diameter: DN50 – DN300

    Flange connection: PN10, PN16, ANSI 150

    Case material: Stainless steel (1.4408)

    Flap seal: EPDM

    Operations: Electric, Pneumatic double-acting & single-acting, Hand lever, Gearbox

  • PTFE butterfly valve, flanged type AK131

    PTFE butterfly valve, flanged type AK131

    Nominal diameter: DN50 – DN300

    Flange connection: PN10, PN16, Optional Flanschbohrung 150lbs

    Case material: EN-GSJ-500-7 (GGG50) spheroidal graphite cast iron

    Flap seal: PTFE

    Operations: Electric, Pneumatic double-acting & single-acting, Hand lever, Gearbox

  • Double-eccentric butterfly valve type AX131

    Double-eccentric butterfly valve type AX131

    Connection: PN10, PN16, ANSI 150 (on request)

    Face-to-face: EN 558-1, Series 20; ISO 5752 Series 20

    Tightness class: Class V / ISO 5208, leakage rate AA

    Body: ASTM A351 CF8M, ASTM A216 WCB

    Zulassung: TA Luft (ISO 15848), ATEX according to 2014/34/EU – Atex II 2GDc

  • Double-offset butterfly valve type AX130

    Double-offset butterfly valve type AX130

    Connection: PN10, PN16, ANSI 150

    Face-to-face: EN 558-1, Series 20; ISO 5752 Series 20

    Tightness class: Class V / ISO 5208, leakage rate AA

    Seat ring: RPTFE (PTFE + 25%GF), INCONEL 718

    Zulassung: TA Luft (ISO 15848), ATEX according to 2014/34/EU – Atex II 2GDc

Product Overview

Butterfly Valves – DN25 to DN1200, PN6 to PN16, Centric and Double Eccentric

The butterfly valve uses a disc that rotates 90° (quarter turn) to open or close the flow passage. Compared to the ball valve, the butterfly valve offers a significantly shorter face-to-face length and lower weight at the same nominal diameter, making it the most economical solution for large sizes. With centric bearing, the shaft axis lies in the pipe centre. With double eccentric bearing, the shaft is offset in two directions, so the disc swings clear of the seat upon opening — reducing wear. Ductile iron butterfly valves comply with EN 593.

Fergo offers a comprehensive range. The Fergo butterfly valves AK200 (wafer) and AK201 (lug) are in ductile iron GGG40 with 150 µm epoxy coating, stainless steel disc CF8M, shaft AISI 420 and seat ring EPDM, NBR or FKM, DN25 to DN1200. The stainless steel butterfly valves feature a body fully in CF8M. The DVGW butterfly valves are certified per DIN EN 13774. The PTFE butterfly valves protect all wetted surfaces with a continuous fluoropolymer lining. The double eccentric butterfly valves in GGG50 with RPTFE/INCONEL metal seat cover higher pressures and temperatures. The vacuum butterfly valves are designed for sub-atmospheric applications. All series feature the ISO 5211 top flange for pneumatic and electric J4C actuators.

Designed for water treatment, drinking water and gas supply, HVAC, chemical processing, petrochemicals, food and beverage, power generation, fire protection and municipal infrastructure. For automation, a NAMUR solenoid valve and a Switchmaster limit switch box are recommended.

Butterfly Valve Types at Fergo

01 Fergo Butterfly Valves – Wafer and Lug Type

The Fergo butterfly valves AK200 (wafer) and AK201 (lug) are in ductile iron GGG40 with 150 µm epoxy coating, stainless steel disc CF8M, shaft AISI 420 and seat ring EPDM, NBR or FKM. DN25 to DN300 as standard with hand lever, up to DN1200 with worm gearbox. Wafer type is clamped between two pipe flanges. Lug type has threaded inserts for end-of-line installation and single-side dismantling.

02 Stainless Steel Butterfly Valves

The stainless steel butterfly valves feature body, disc and shaft fully in CF8M (1.4408) for chemical processing, pharmaceuticals, food and beverage and corrosive media. DN25 to DN300, PN10/16 and ANSI Class 150. Full-stainless-steel construction ensures highest media purity without coating wear.

03 DVGW Butterfly Valves – Gas and Drinking Water

The DVGW butterfly valves of the AK210G/AK211G (gas, NBR seat) and AK210W/AK211W (drinking water, EPDM seat) series are certified per DVGW DIN EN 13774, DN25 to DN600. These valves meet the legal requirements for public water supply, gas distribution networks and building services.

04 Pneumatic Butterfly Valves

The pneumatic butterfly valves comprise pre-assembled units of butterfly valve and pneumatic quarter-turn actuator, either double-acting (DA) or single-acting spring return (SR) with fail-safe function. Available from DN25 to DN300 online, DN300 to DN1200 on request. ATEX certification for hazardous areas available.

05 Electric Butterfly Valves

The electric butterfly valves comprise pre-assembled units with J4C electric quarter-turn actuator, multi-voltage 24V–240V AC/DC, IP67 protection. Options include positioners with 0–10 V or 4–20 mA for proportional control and BSR battery backup for fail-safe operation.

06 PTFE-Lined Butterfly Valves

The PTFE-lined butterfly valves protect disc, seat ring and body bore with a continuous PTFE lining. Body in GGG50, disc in CF8M, PTFE near-total chemical inertness. DN40 to DN300, PN10/16 and ANSI Class 150. Right choice for acids, alkalis, solvents and high-purity media.

07 Double Eccentric Butterfly Valves

The double eccentric butterfly valves in GGG50 with double-offset shaft and RPTFE/INCONEL metal seat for PN16–PN40 and temperatures up to +400 °C. Disc swings clear of seat immediately upon opening — wear is drastically reduced. Typical applications: steam, hot gases, thermal oil and high cycle counts.

08 Vacuum Butterfly Valves

The vacuum butterfly valves are designed for sub-atmospheric and vacuum applications in process industry, chemical and semiconductor manufacturing.

Materials in Detail: Specifying the Right Butterfly Valve

Materials of the Butterfly Valves – Body, Disc, Shaft and Seat Ring

1. Ductile Iron GGG40 (EN-GJS-400-15) with Epoxy Coating

Application: water, drinking water, gas, HVAC, fire protection, municipal infrastructure.
Temperature: –10 °C to +120 °C (with EPDM seat ring).
Advantages: high mechanical strength, water hammer resistance, 150 µm epoxy coating.
Limitations: not suited for strongly corrosive media without lining.

2. Ductile Iron GGG50 (EN-GJS-500-7)

Application: double eccentric butterfly valves and PTFE-lined butterfly valves.
Temperature: up to +400 °C (RPTFE/INCONEL) or +200 °C (PTFE).
Advantages: higher tensile strength than GGG40, suited for PN16–PN40.
Limitations: higher cost than GGG40.

3. Stainless Steel CF8M (1.4408 / AISI 316)

Application: chemical processing, pharmaceuticals, food and beverage, corrosive media.
Temperature: –30 °C to +180 °C (with PTFE seat ring).
Advantages: full corrosion resistance, highest media purity.
Limitations: higher unit cost than GGG40.

4. Seat Ring EPDM

Application: drinking water, hot water, HVAC.
Temperature: –10 °C to +120 °C.
Advantages: DVGW-approved for drinking water, ozone and UV resistant.
Limitations: not suited for mineral oils and hydrocarbons.

5. Seat Ring NBR

Application: gas, compressed air, mineral oil, hydrocarbons.
Temperature: –10 °C to +80 °C.
Advantages: DVGW-approved for gas.
Limitations: not suited for ozone and UV.

6. Seat Ring FKM (Viton)

Application: solvents, hydrocarbons, acids, petrochemicals.
Temperature: –10 °C to +180 °C.
Advantages: extended chemical resistance and high-temperature capability.
Limitations: not suited for ketones and esters.

7. PTFE Lining

Application: acids, alkalis, solvents and high-purity media.
Temperature: –25 °C to +200 °C.
Advantages: near-total chemical inertness.
Limitations: lower mechanical strength than metal seats.

8. RPTFE/INCONEL Metal Seat (Double Eccentric)

Application: steam, hot gases, abrasive media, high cycle counts.
Temperature: up to +400 °C.
Advantages: lasting sealing at high temperatures.
Limitations: bubble-tight sealing at very low differential pressure not guaranteed.

Centric vs Double Eccentric

Centric or Double Eccentric Butterfly Valve – Operating Principle and Selection

The choice between centric and double eccentric bearing determines wear behaviour, pressure rating, maximum temperature and service life.

Centric Butterfly Valve

With centric bearing, the shaft axis lies in the pipe centre and in the seat plane. The disc slides over the elastomer seat ring on opening and closing. Simple, compact and cost-effective. Standard for water, drinking water, gas, HVAC and fire protection at PN6–PN16 and up to +120 °C (EPDM) or +180 °C (FKM). The AK200, AK201 and all DVGW series at Fergo are centric.

Double Eccentric Butterfly Valve

The shaft axis is offset in two directions: behind the seat plane (axial offset) and to the side of the pipe centre (lateral offset). The disc swings clear of the seat immediately on opening. Seat ring wear is drastically reduced. Metal seats (RPTFE/INCONEL) enable temperatures up to +400 °C and PN16–PN40. Typical applications: steam, hot gases, thermal oil, abrasive media and high cycle counts.

Selection Guide

Centric is the right choice for standard applications — optimal cost-performance. Double eccentric is the right choice for steam, hot gases and pressures above PN16.

Certifications and Standards of Fergo Butterfly Valves

Fergo butterfly valves comply with EN 593 for metallic butterfly valves, EN 558-1 series 20/13 for face-to-face dimensions, EN 1092-2 for flanged connections and ASME B16.5 Class 150. DVGW certification per DIN EN 13774 applies to AK210G/AK211G (gas) and AK210W/AK211W (drinking water). PED 2014/68/EU is covered for applicable models. ATEX 2014/34/EU for hazardous areas.

Factory certificates on the Fergo certificates page. Seat ring compatibility via the chemical resistance tool.

Delivery and Availability of Butterfly Valves

Fergo offers over 25 000 butterfly valve references from stock in Neuss, Germany. DHL 2–7 working days. Terms on the shipping and payment terms page.

For projects, Fergo develops customised solutions.