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Industriearmaturen Knife Gate Valve

Knife Gate Valves and Slurry Valves – Wafer Type in Cast Iron and Stainless Steel

Fergo supplies knife gate valves (also called wafer gate valves, slide gate valves, slurry valves, flat gate valves or guillotine valves) with wafer-type body for reliable shut-off of fibre-, granulate- and slurry-laden media. Available in grey cast iron GG25 and stainless steel CF8M (1.4408), from DN50 to DN600, PN10 (PN16 on request), uni-directional or bi-directional, with NBR, EPDM or metal seat ring, actuated by handwheel, pneumatic actuator or quick-closing lever.

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DN50 to DN600

PN10 (PN16 on request)

Seat ring types

NBR, EPDM, metallic

Gland packing

PTFE, graphite, PTFE+NBR, PTFE+EPDM, PTFE+Viton

Knife Gate Valve
  • Knife Gate Valve FM200 – Unidirectional

    Knife Gate Valve FM200 – Unidirectional

    Sizes: DN50 – DN1200

    Flange connection: PN10, ANSI 150, PN16

    Case material: GG25, GGG40, 1.4408, 1.4571

    Slide plate: 1.4301, 1.4408, 1.4571, Hardox

    Gland Packing: PTFE, Graphite, PTFE+NBR, PTFE+EPDM, PTFE+Viton

    Sealing ring: NBR, EPDM, silicone, Viton, PTFE, Flucast ABP, metallic

  • Knife Gate Valve FB200 – Bidirectional

    Knife Gate Valve FB200 – Bidirectional

    Sizes: DN50 – DN1200

    Flange connection: PN10, ANSI 150, PN16

    Case material: GG25, GGG40, 1.4408, 1.4571

    Slide plate: 1.4301, 1.4408, 1.4571, Hardox

    Gland Packing: PTFE, Graphite, PTFE+NBR, PTFE+EPDM, PTFE+Viton

    Sealing ring: NBR, EPDM, silicone, Viton, PTFE, Flucast ABP, metallic

  • Knife Gate Valve Type FB700

    Knife Gate Valve Type FB700

    Sizes: DN50 – DN250

    Flange connection: PN10, ANSI 150, PN16

    Case material: GG25, GGG40, 1.4408, 1.4571

    Slide plate: 1.4301, 1.4408, 1.4571, Hardox

    Gland Packing: PTFE+NBR, PTFE+EPDM, PTFE+Viton

    Sealing ring: NBR, EPDM, Viton

  • Slurry Gate Valve Type FL300

    Slurry Gate Valve Type FL300

    Sizes: DN50 – DN500, (Larger on request)

    Flange connection: PN10, ANSI 150, PN16

    Case material: GG25, 1.4408, 1.4571

    Slide plate: 1.4301, 1.4408, 1.4571, Hardox

    Gland Packing: PTFE, Graphite, PTFE+NBR, PTFE+EPDM, PTFE+Viton

    Sealing ring: NBR, EPDM, Silicone, Viton, PTFE, Flucast ABP

  • Double-Plate Knife Gate Valve Type FL500

    Double-Plate Knife Gate Valve Type FL500

    Sizes: DN200, DN250, DN300, DN350, DN400, DN450, DN500, DN600, (Larger on request)

    Flange connection: PN10, PN16

    Case material: 1.4408, 1.0619

    Slide plate: 1.4301, 1.4408, 1.4571

    Gland Packing: Carbographite, Ceramic

    Sealing ring: NBR, EPDM, Silicone, Viton, Metallic

  • Silo Gate Valve Type FG400

    Silo Gate Valve Type FG400

    Sizes: DN50 – DN600, (Larger on request)

    Flange connection: PN10, ANSI 150, PN16

    Case material: GG25, 1.4408, 1.4571

    Slide plate: 1.4301, 1.4408, 1.4571, Hardox

    Gland Packing: Graphite, PTFE+NBR, PTFE+EPDM, PTFE+Viton

    Sealing ring: NBR, EPDM, Silicone, Viton, PTFE, Flucast ABP

  • Rectangular Gate Valve Type FC

    Rectangular Gate Valve Type FC

    Case material: 1.0619, 1.4301

    Slide plate: 1.4301, 1.4408, 1.4571, Hardox

    Gland Packing: Graphite, PTFE+NBR, PTFE+EPDM, PTFE+Viton

    Sealing ring: NBR, EPDM, Silicone, Viton, PTFE, Metallic

    Connection: Flanges

    Operations: Sprocket, Electric motor, Pneumatic double-acting, Pneumatic single-acting, Quick-closing hand lever, Gearbox with handwheel, Handwheel

  • FH650 High-Pressure Knife Gate Valve

    FH650 High-Pressure Knife Gate Valve

    Sizes: DN80 – DN500 (larger on request)

    Flange connection: PN10, ANSI 150, PN16, PN40, PN25, PN64, PN100

    Case material: 1.4571, 1.0619, 1.4401, 1.4462

    Slide plate: 1.4301, 1.4408, 1.4571, Hardox

    Gland Packing: PTFE, graphite, carbographite

    Sealing ring: NBR, EPDM, silicone, Viton, metal-seated, soft metal-seated

Produktübersicht

Knife Gate Valves – DN50 to DN600, PN10, Cast Iron and Stainless Steel, Uni-Directional and Bi-Directional

The knife gate valve, also known as wafer gate valve, slurry valve, slide gate valve, flat gate valve or guillotine valve, is a linear shut-off valve with a sharp-edged gate plate. The plate travels through the medium guillotine-style and cuts fibres, granulates or sludge instead of trapping them like a ball valve or butterfly disc. This design makes the knife gate valve the right choice for pulp, paper stock, wastewater, sludge, mining slurry, granulates, fibres, bentonite, lime slurry and other solids-laden media. Face-to-face length follows EN 558 series 20; flanged connections comply with EN 1092-1. The wafer knife gate valve is clamped between two pipeline flanges — fast, cost-effective and directly interchangeable with existing valves.

Fergo offers two series. The FM200 series is a uni-directional wafer knife gate valve with soft seat (NBR, EPDM) or metal seat. The FB700 series is a bi-directional knife gate valve with U-profile seal, steel-core-reinforced profile and integrated plate guide with scraping effect — the right choice for backflow-tight duty and abrasive media. Both series are available with handwheel actuation (rising stem), pneumatic actuator (double-acting, combinable with sensors, NAMUR valve and limit switch box) and quick-closing lever. The gate plate is standard stainless steel SS304L (1.4306) for GG25 bodies and SS316L (1.4404) for stainless steel bodies; stem in SS303 (1.4305).

Typical applications: pulp and paper industry, wastewater treatment and sewage plants, chemical processing, mining and processing, food and beverage, cement industry, power plant technology and pneumatic solids conveying. To protect downstream fittings against solids, a Y-strainer is recommended; for control duty downstream, ball valves and butterfly valves are the natural fit.

Knife Gate Valve Categories at Fergo

01 Knife Gate Valves – Wafer Type Design

The knife gate valves category covers all FM200 and FB700 models in wafer type. The wafer knife gate valve is clamped between two pipeline flanges PN10/PN16 per EN 1092-1. Nominal sizes from DN50 to DN600, face-to-face length per EN 558 series 20. Benefits: short face-to-face length, low weight, direct interchange with existing valves without pipe modification. The plate guide with integrated scraping effect cleans the seat ring at every stroke — essential for long service life in pulp and paper duty.

02 Stainless Steel Knife Gate Valves – CF8M (1.4408) body

For automated processes, Fergo supplies pneumatic knife gate valves with a double-acting or spring-return actuator (fail-to-close). The actuators are prepared for NAMUR solenoid valves and limit switch boxes, so the valve integrates directly into the process control system. Actuator mounting follows an ISO 5211 flange. Electric actuators such as the J4C actuator are available as well.

03 Quick-Closing Lever Knife Gate Valves

The stainless steel knife gate valves feature a body in stainless steel CF8M (1.4408 / AISI 316), gate plate in SS316L (1.4404) and stem in SS303 (1.4305). Nominal sizes from DN50 to DN600, PN10. Temperature range –20 °C to +120 °C with EPDM seat, +90 °C with NBR seat. This version is the right choice for chemical processing, pharmaceuticals, food and beverage, drinking water and all corrosive or hygienically sensitive media. Available with handwheel, pneumatic actuator or quick-closing lever.

04 Cast Iron Knife Gate Valves – GG25 – the economical standard

The cast iron knife gate valves feature a body in grey cast iron GG25 (EN-JL1040), gate plate in SS304L (1.4306) and stem in SS303 (1.4305). Nominal sizes from DN50 to DN600, PN10. Grey cast iron GG25 offers excellent cost-performance ratio, high mechanical strength and excellent vibration damping. This version is the standard solution for pulp and paper, wastewater, sludge, bentonite, cement and pneumatic solids conveying. Temperature range up to +90 °C (NBR) or +120 °C (EPDM).

05 Pneumatic Knife Gate Valves – double-acting actuator

The pneumatic knife gate valves comprise FM200 and FB700 models with pre-mounted pneumatic double-acting cylinder. The pneumatic knife gate valve enables fast actuation (opening and closing in seconds) and is the right choice for automated process plants with high cycle counts. The pneumatic actuator is combinable with NAMUR solenoid valves and Switchmaster limit switch boxes per VDI/VDE 3845. Optional with IFM IFT206 inductive sensors and ATEX certification for hazardous areas.

06 Handwheel Knife Gate Valves – rising stem

The handwheel knife gate valves are equipped with a rising stem and a robust handwheel. The gear ratio converts hand force into sufficient thrust to open and close the gate plate reliably even against back pressure — no compressed air, no electrics. The right choice for manual shut-off in solids lines, for maintenance points and for plants without automation demand.

Materials in Detail: Specifying the Right Knife Gate Valve

Materials of the Knife Gate Valves – Body, Gate Plate, Stem and Seat Ring

1. Grey Cast Iron GG25 (EN-JL1040) – Body

Application: pulp, paper stock, wastewater, sludge, mining slurry, cement, bentonite, pneumatic solids conveying, lime slurry.
Temperature: –20 °C to +90 °C (NBR) or +120 °C (EPDM).
Advantages: excellent cost-performance ratio, high mechanical strength, excellent vibration damping, the standard solution for slurry valves in paper and wastewater industries for decades.
Limitations: not suited for strongly corrosive media and drinking water without internal coating.

2. Stainless Steel CF8M (1.4408 / AISI 316) – Body

Application: chemical processing, pharmaceuticals, food and beverage, hygienically sensitive applications, corrosive media, saline and acidic fluids.
Temperature: –20 °C to +120 °C (EPDM) or +90 °C (NBR).
Advantages: full corrosion resistance, high media purity, no internal coating required, significantly longer service life than GG25 in aggressive media.
Limitations: higher unit cost than cast iron.

3. Gate Plate – Stainless Steel SS304L (1.4306) and SS316L (1.4404)

SS304L (1.4306): standard gate plate for cast iron bodies. Sharp-edged for guillotine-style cutting through fibres and granulates.
SS316L (1.4404): gate plate for stainless steel bodies. Higher corrosion resistance for chemical and hygienic applications.
Advantages: form stability, corrosion resistance, blow-out proof guidance via the plate guide with integrated scraping effect (FB700).

4. Stem – Stainless Steel SS303 (1.4305)

Standard material: free-cutting steel SS303 for the rising stem in handwheel actuation and for the piston rod in pneumatic actuators.
Advantages: corrosion resistance, excellent machinability for precise thread geometry, good concentricity.

5. Seat Ring NBR

Application: standard for pulp, paper stock, wastewater, mineral oil, aliphatic hydrocarbons and oil-laden media.
Temperature: –20 °C to +90 °C.
Advantages: good mechanical resistance, cost-effective, wide availability.
Limitations: not resistant to ozone, UV and aromatic hydrocarbons.

6. Seat Ring EPDM

Application: drinking water, hot water, HVAC, alkalis, diluted acids, glycol-based brake fluids.
Temperature: –20 °C to +120 °C.
Advantages: ozone-, UV- and ageing-resistant, higher temperatures than NBR.
Limitations: not suited for mineral oils and hydrocarbons.

7. Seat Ring Metal

Application: dry conveying, abrasive media, granulates, cement, high temperatures and applications with vapour content.
Advantages: high wear resistance, no elastomer cold flow, suitable above the EPDM limit.
Limitations: not bubble-tight at very low differential pressure — select by tightness requirement.

8. U-Profile Seal with Steel Core Reinforcement (FB700)

Application: bi-directional design for backflow-tight duty and abrasive media.
Construction: elastomer profile (NBR or EPDM) with embedded steel core reinforcement. The plate guide with integrated scraping effect cleans the seat ring at every stroke.
Advantages: long service life in pulp and paper duty, reliable sealing in both flow directions.

Uni-Directional vs Bi-Directional – FM200 or FB700

Uni-Directional or Bi-Directional Knife Gate Valve – FM200 vs FB700

The choice between uni-directional knife gate valve (FM200) and bi-directional knife gate valve (FB700) determines backflow tightness, seat ring geometry and service life in abrasive media.

FM200 – Uni-Directional

The FM200 is a uni-directional wafer knife gate valve. The soft seat (NBR, EPDM or metal) sits only on one side of the body. The right choice for a defined flow direction and for applications without backflow requirement. Economical, compact and with the widest range: DN50 to DN600, handwheel, pneumatic, quick-closing, cast iron or stainless steel.

FB700 – Bi-Directional

The FB700 is a bi-directional knife gate valve with U-profile seal and steel-core reinforcement. The elastomer seal encloses the gate plate from both sides — tight in both flow directions. The plate guide with integrated scraping effect cleans the seat ring at every stroke and extends service life in pulp, paper stock and slurry duty. The right choice with possible backflow, particularly abrasive media and high cycle counts.

Selection Guide

FM200: the right choice for standard shut-off with defined flow direction — best cost-performance ratio. FB700: the right choice for backflow tightness, abrasive media and long service-life requirement.

Certifications and Standards of Fergo Knife Gate Valves

Fergo knife gate valves comply with the key European and international standards. Face-to-face length follows EN 558 series 20 — the standard face-to-face length for wafer-type valves. Flanged connections comply with EN 1092-1 (cast iron and stainless steel) and ASME B16.5 Class 150 (on request). Testing follows EN 12266-1 for seat and shell tightness. PED 2014/68/EU is covered for applicable models. Optional ATEX certification per 2014/34/EU for hazardous areas on pneumatic and electric actuators.

Factory certificates, 3D models and technical datasheets are available on the Fergo certificates page. Seat ring elastomer and body material compatibility with specific media can be checked via the chemical resistance tool.

Delivery and Availability of Knife Gate Valves

Fergo offers over 400 knife gate valve and slurry valve references from stock in Neuss, Germany. Shipping covers the UK, Europe and worldwide. Standard delivery via DHL is 2–7 working days; freight forwarder shipping for DN400+. All terms are detailed on the shipping and payment terms page.

For projects requiring a pre-assembled valve-actuator unit, a PN16 version, a special material (duplex, Hastelloy), a special seat ring or a custom face-to-face length, Fergo develops customised solutions.