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Knife Gate Valves with Handwheel – Robust Shut-Off Technology for Demanding Media

When it comes to isolating viscous, abrasive, or solids-laden media in industrial piping systems, a knife gate valve with handwheel is often the most reliable solution. These robust valves, also known as slurry or solids-handling valves, operate on a simple yet highly effective principle: a sharp-edged gate cuts directly through the flow and provides a tight shut-off.

Unlike wedge gate valves, knife gate valves are specifically designed for challenging media such as slurries, wastewater, pulp, or bulk solids. Manual operation via handwheel offers direct control, high operational reliability, and long service life. This makes them ideal for applications where automation is not required or where simplicity and safety are paramount.

Manual knife gate valves are also well suited for use in hazardous or explosion-risk areas, as they operate independently of electrical or pneumatic power sources. Their straightforward design minimizes maintenance requirements while ensuring dependable performance under tough operating conditions.

FERGO offers high-quality knife gate valves from the FB200 series, manufactured in cast iron and stainless steel. These valves are engineered to meet the specific demands of your industry, combining durability, precise shut-off, and proven reliability.

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SUBCATEGORIES
Pnuematisch-Plattenschieber
Pneumatic Knife Gate Valves
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Schnellschluhebel
Knife Gate Valves Lever
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PRODUCT CONFIGURATOR

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20 item (s) of 78
FM200 Knife gate valve DN 150 EPDM stainless-steel handwheel rising stem
Product number
Copy to clipboard 270-1005-14
Knife gate valve DN 150 PN10 Wafer-type unidirectional design, body made of stainless steel CF8M(1.4408), gate made of stainless steel SS316L (1.4404), stem made of stainless steel SS303 (1.4305), seat ring made of EPDM, actuation: handwheel with rising stem
Slider plate:
Stainless steel SS304L (1.4306)
Slider plate:
Stainless steel SS316L (1.4404)
Nominal width :
DN150 - 6'' inch
Seat:
EPDM
Design :
sealing on one side
Body:
Stainless Steel
Price €817.49
€972.81 incl. VAT
Delivery Time: in stock
Available: In Stock
FM200 Knife-gate valve DN 65 NBR Cast iron Handwheel with rising stem
Product number
Copy to clipboard 270-1001-10
Knife gate valve DN 65 PN10Single-seated design, seat ring made of NBR, body made of grey cast iron (GG25), gate valve plate made of stainless steel SS304L (1.4306), stem made of stainless steel SS303 (1.4305), actuation handwheel with rising stem
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN65 - 2 1/2'' inch
Design :
sealing on one side
Seat:
NBR
Body:
Grey Cast Iron
Actuation :
Handwheel (rising stem)
Price €253.80
€302.02 incl. VAT
Delivery Time: in stock
Available: In Stock
FB700 Knife-gate valve DN 80 EPDM Cast iron GG25 Handwheel with rising stem
Product number
Copy to clipboard 270-3000-11
Wafer type knife gate valve DN 80 PN10Double sealing design, seat ring made of EPDM with profile steel core reinforcement, body made of grey cast iron (GG25), gate plate & stem made of stainless steel, plate guide with integrated scraping effect, packing PTFE-Synt./EPDM/PTFE-Synt, operation handwheel with rising stem
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN80 3'' inch
Design :
sealing on both sides
Seat:
EPDM
Body:
Grey Cast Iron
Actuation :
Handwheel (rising stem)
Price €309.46
€368.26 incl. VAT
Delivery Time: in stock
Available: In Stock
FB700 Knife-gate valve DN 100 EPDM cast iron handwheel with rising stem
Product number
Copy to clipboard 270-3000-12
Knife gate valve DN 100 PN10Double poppet design, seat ring made of EPDM with profile steel core reinforcement, body made of grey cast iron (GG25), gate plate & stem made of stainless steel, plate guide with integrated scraping effect, packing PTFE-Synt./EPDM/PTFE-Synt, operation handwheel with rising stem
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN100 - 4'' inch
Design :
sealing on both sides
Seat:
EPDM
Body:
Grey Cast Iron
Actuation :
Handwheel (rising stem)
Price €343.73
€409.04 incl. VAT
Delivery Time: in stock
Available: In Stock
FB700 Knife-gate valve DN 250 NBR Cast iron GG25 Handwheel
Product number
Copy to clipboard 270-3131-18
Flanged knife gate valve DN 250 PN10Design bi-directional, seat ring made of NBR with profile steel core reinforcement, body made of grey cast iron (GG25), gate plate & stem made of stainless steel, handwheel with non-rising stem
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN250 - 10'' inch
Design :
sealing on both sides
Seat:
NBR
Body:
Grey Cast Iron
Actuation :
Handwheel (non-rising)
Price €1,048.32
€1,247.50 incl. VAT
Delivery Time: in stock
Available: In Stock
FM200 Knife-gate valve DN 150 NBR Cast iron Handwheel with rising stem
Product number
Copy to clipboard 270-1001-14
Knife gate valve DN 150 PN10Single-seated design, seat ring made of NBR, body made of grey cast iron (GG25), gate valve plate made of stainless steel SS304L (1.4306), stem made of stainless steel SS303 (1.4305), actuation handwheel with rising stem
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN150 - 6'' inch
Design :
sealing on one side
Seat:
NBR
Body:
Grey Cast Iron
Actuation :
Handwheel (rising stem)
Price €387.00
€460.53 incl. VAT
Delivery Time: in stock
Available: In Stock
FM200 Knife-gate valve DN 200 EPDM Cast iron Handwheel with rising stem
Product number
Copy to clipboard 270-1000-16
Knife gate valve DN 200 PN10 Single-seated design, seat ring made of EPDM, body made of grey cast iron (GG25), gate valve plate made of stainless steel SS304L (1.4306), stem made of stainless steel SS303 (1.4305), packing: PTFE-Synt./EPDM/PTFE-Synt, operation handwheel with rising stem
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN200 - 8'' inch
Seat:
EPDM
Design :
sealing on one side
Body:
Grey Cast Iron
Actuation :
Handwheel (rising stem)
Price €565.54
€672.99 incl. VAT
Delivery Time: in stock
Available: In Stock
FB700 Knife-gate valve DN 200 NBR Cast iron GG25 Handwheel
Product number
Copy to clipboard 270-3131-16
Flanged knife gate valve DN 200 PN10Design bi-directional, seat ring made of NBR with profile steel core reinforcement, body made of grey cast iron (GG25), gate plate & stem made of stainless steel, handwheel with non-rising stem
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN200 - 8'' inch
Design :
sealing on both sides
Seat:
NBR
Body:
Grey Cast Iron
Actuation :
Handwheel (non-rising)
Price €799.34
€951.21 incl. VAT
Delivery Time: in stock
Available: In Stock
FM200 Knife-gate valve DN 150 NBR Stainless steel handwheel rising stem
Product number
Copy to clipboard 270-1015-14
Knife gate valve DN 150 PN10 stainless steelSingle-seated design, seat ring made of NBR, body made of stainless steel CF8M(1.4408), gate valve plate made of stainless steel SS316L (1.4404), stem made of stainless steel SS303 (1.4305), actuation handwheel with rising stem
Slider plate:
Stainless steel SS304L (1.4306)
Slider plate:
Stainless steel SS316L (1.4404)
Nominal width :
DN150 - 6'' inch
Design :
sealing on one side
Seat:
NBR
Body:
Stainless Steel
Price €817.49
€972.81 incl. VAT
Delivery Time: in stock
Available: In Stock
FB700 Knife-gate valve DN 150 EPDM cast iron handwheel with rising stem
Product number
Copy to clipboard 270-3000-14
Sandwich knife gate valve - knife gate valve DN 150 PN10Design bi-directional, seat ring made of EPDM with profile steel core reinforcement, body made of grey cast iron (GG25), gate plate & stem made of stainless steel, plate guide with integrated scraping effect, packing PTFE-Synt./EPDM/PTFE-Synt, operation handwheel with rising stem 
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN150 - 6'' inch
Design :
sealing on both sides
Seat:
EPDM
Body:
Grey Cast Iron
Actuation :
Handwheel (rising stem)
Price €446.54
€531.38 incl. VAT
Delivery Time: in stock
Available: In Stock
FM200 Knife-gate valve DN 150 EPDM Cast iron Handwheel with rising stem
Product number
Copy to clipboard 270-1000-14
Knife gate valve DN 150 PN10Single-seated design, seat ring made of EPDM, body made of grey cast iron (GG25), gate made of stainless steel SS304L (1.4306), stem made of stainless steel SS303 (1.4305), packing: PTFE-Synt./EPDM/PTFE-Synt, operation handwheel with rising stem
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN150 - 6'' inch
Seat:
EPDM
Design :
sealing on one side
Body:
Grey Cast Iron
Actuation :
Handwheel (rising stem)
Price €387.00
€460.53 incl. VAT
Delivery Time: in stock
Available: In Stock
FM200 Knife-gate valve DN 80 EPDM Cast iron Handwheel with rising stem
Product number
Copy to clipboard 270-1000-11
Knife gate valve DN 80 PN10Single-seated design, seat ring made of EPDM, body made of grey cast iron (GG25), gate made of stainless steel SS304L (1.4306), stem made of stainless steel SS303 (1.4305), packing: PTFE-Synt./EPDM/PTFE-Synt, operation handwheel with rising stem
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN80 3'' inch
Seat:
EPDM
Design :
sealing on one side
Body:
Grey Cast Iron
Actuation :
Handwheel (rising stem)
Price €274.32
€326.44 incl. VAT
Delivery Time: in stock
Available: In Stock
FM200 Knife gate valve DN 100 EPDM stainless-steel handwheel rising stem
Product number
Copy to clipboard 270-1005-12
Knife gate valve DN 100 PN10 Wafer-type unidirectional design, body made of stainless steel CF8M(1.4408), gate made of stainless steel SS316L (1.4404), stem made of stainless steel SS303 (1.4305), seat ring made of EPDM, actuation: handwheel with rising stem
Slider plate:
Stainless steel SS304L (1.4306)
Slider plate:
Stainless steel SS316L (1.4404)
Nominal width :
DN100 - 4'' inch
Seat:
EPDM
Design :
sealing on one side
Body:
Stainless Steel
Price €573.55
€682.52 incl. VAT
Delivery Time: in stock
Available: In Stock
FM200 Knife-gate valve DN 100 NBR Cast iron Handwheel with rising stem
Product number
Copy to clipboard 270-1001-12
Wafer type knife gate valve DN 100 PN10 Single-seated design, seat ring made of NBR, body made of grey cast iron (GG25), gate plate made of stainless steel SS304L (1.4306), stem made of stainless steel SS303 (1.4305), actuation handwheel with rising stem
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN100 - 4'' inch
Design :
sealing on one side
Seat:
NBR
Body:
Grey Cast Iron
Actuation :
Handwheel (rising stem)
Price €288.96
€343.86 incl. VAT
Delivery Time: in stock
Available: In Stock
FM200 Knife-gate valve DN 350 NBR Cast iron Handwheel with rising stem
Product number
Copy to clipboard 270-1001-22
Wafer-type knife gate valve/flat knife gate valve DN 350 PN10, single-seated design, seat ring made of NBR, body made of grey cast iron (GG25), gate plate made of stainless steel SS304L (1.4306), stem made of stainless steel SS303 (1.4305), actuation handwheel with rising stem
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN350 - 14'' inch
Design :
sealing on one side
Seat:
NBR
Body:
Grey Cast Iron
Actuation :
Handwheel (rising stem)
Price €1,839.02
€2,188.43 incl. VAT
Delivery Time: 1-2 weeks
Available: In Stock
FB700 Knife-gate valve DN 250 EPDM Cast iron Stainless steel Handwheel with rising stem
Product number
Copy to clipboard 270-3000-18
Wafer-type knife gate valve/flat knife gate valve DN250 PN10, double-seated design, seat ring made of EPDM with profile steel core reinforcement, body made of grey cast iron (GG25), gate plate & stem made of stainless steel, plate guide with integrated scraping effect, packing PTFE-Synt./EPDM/PTFE-Synt, actuation handwheel with rising stem, nominal pressure 10 bar
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN250 - 10'' inch
Design :
sealing on both sides
Seat:
EPDM
Body:
Grey Cast Iron
Actuation :
Handwheel (rising stem)
Price €822.53
€978.81 incl. VAT
Delivery Time: in stock
Available: In Stock
FM200 Knife gate valve DN 300 metallic cast iron Handwheel with rising stem
Product number
Copy to clipboard 270-1002-20
Wafer type knife gate valve DN 300 PN10Single-seated design, seat ring made of metal, body made of grey cast iron (GG25), gate valve plate made of stainless steel SS304L (1.4306), stem made of stainless steel SS303 (1.4305), actuation handwheel with rising stem
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN300 - 12'' inch
Design :
sealing on one side
Seat:
Metallic
Body:
Grey Cast Iron
Actuation :
Handwheel (rising stem)
Price €912.29
€1,085.63 incl. VAT
Delivery Time: in stock
Available: In Stock
FB700 Knife-gate valve DN 50 NBR Cast iron GG25 Handwheel with rising stem
Product number
Copy to clipboard 270-3001-09
Wafer type knife gate valve DN 50 PN10double seated design, seat ring made of NBR with profile steel core reinforcement, body made of grey cast iron (GG25), knife gate plate & stem made of stainless steel, knife gate guide with integrated scraping effect, packing PTFE-Synt./NBR/PTFE-Synt, actuation handwheel with rising stem
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN50 - 2'' inch
Design :
sealing on both sides
Seat:
NBR
Body:
Grey Cast Iron
Actuation :
Handwheel (rising stem)
Price €284.26
€338.27 incl. VAT
Delivery Time: in stock
Available: In Stock
FM200 Knife gate valve DN 150 Handwheel with rising stem
Product number
Copy to clipboard 270-1002-14
Wafer type knife gate valve DN 150 PN10Single-seated design, seat ring made of metal, body made of grey cast iron (GG25), gate plate made of stainless steel SS304L (1.4306), stem made of stainless steel SS303 (1.4305), actuation handwheel with rising stem
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN150 - 6'' inch
Design :
sealing on one side
Seat:
Metallic
Body:
Grey Cast Iron
Actuation :
Handwheel (rising stem)
Price €359.14
€427.38 incl. VAT
Delivery Time: in stock
Available: In Stock
FM200 Knife-gate valve DN 80 Metal cast iron Handwheel with rising stem
Product number
Copy to clipboard 270-1002-11
Wafer-type knife gate valve/flat knife gate valve DN 80 PN10, single-seated design, seat ring made of metal, body made of grey cast iron (GG25), gate plate made of stainless steel SS304L (1.4306), stem made of stainless steel SS303 (1.4305), actuation handwheel with rising stem
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN80 3'' inch
Design :
sealing on one side
Seat:
Metallic
Body:
Grey Cast Iron
Actuation :
Handwheel (rising stem)
Price €251.64
€299.45 incl. VAT
Delivery Time: in stock
Available: In Stock

Technical Overview: FERGO Slide Gate Valves with Handwheel

The FB200 series combines proven robustness with precise workmanship. The following table compares the most common variants for manual operation.

Model Type & Part Number

Ideal Application & Media

Technical Specifications & Materials

Special Advantages & FERGO Expertise

FB200-CS1ERW

Standard • Economical

General fluids, water, air, neutral chemicals. Standard applications without special media requirements.

Body: Gray cast iron (GG25).
Gate: Stainless steel SS304L (1.4306).
Seal: EPDM.
Temp. range: -20°C to +120°C.
Actuation: Handwheel.

  • Optimal price-performance ratio for most standard applications.
  • EPDM seal for a wide range of applications with water and neutral media.
  • Robust gray cast iron construction with corrosion-resistant stainless steel gate.

FB200-CS1NRW

For Oils & Fuels

Hydraulic oils, lubricating oils, diesel, gasoline, and other petroleum-based media.

Body: Gray cast iron (GG25).
Gate: Stainless steel SS304L (1.4306).
Seal: NBR.
Temp. range: -20°C to +90°C.
Actuation: Handwheel.

  • Special NBR seal for excellent resistance to mineral oils and fuels.
  • Prevents swelling and damage to the seal upon contact with hydrocarbons.
  • Safe solution for systems in vehicle technology, hydraulics, and industry.

FB200-CS1MRW

High Temperature • Abrasive

Abrasive media (e.g., suspensions, slurries), steam, applications with higher temperatures.

Body: Gray cast iron (GG25).
Gate: Stainless steel SS304L (1.4306).
Seal: Metal.
Temp. range: -20°C to +120°C.
Actuation: Handwheel.

  • Metal seat for extreme wear resistance with abrasive media.
  • For demanding processes where elastomer seals would fail.
  • Long-lasting and reliable solution for harsh industrial environments.

FB200-SSERW

Corrosion-Resistant • Premium

Aggressive chemicals, acids, alkalis, seawater, food and pharmaceutical production.

Body: Stainless steel CF8M (1.4408).
Gate: Stainless steel SS316L (1.4404).
Seal: EPDM.
Temp. range: -20°C to +120°C.
Actuation: Handwheel.

  • Full stainless steel construction for maximum corrosion resistance.
  • Ideal for hygienic and corrosive environments (chemical, pharmaceutical, food).
  • Offers highest material quality and durability for demanding processes.

Advantages of Manual Handwheel Operation

Choosing a knife gate valve with manual handwheel operation offers several decisive advantages:

  • Reliability & independence: No electrical power or compressed air required. Ideal for emergency shut-off functions or remote installations.
  • Simple operation & clear position indication: The rising stem allows the valve position to be identified at a glance – a fully raised stem indicates unrestricted flow.
  • Robust design & ease of maintenance: The mechanical construction is resistant to harsh conditions and easy to service. On many models, the cross seal can be adjusted while the valve remains installed.
  • Cost efficiency: Lower initial investment and operating costs compared to automated valve solutions.

Typical Applications for Handwheel-Operated Knife Gate Valves

Due to their design, knife gate valves are particularly suitable for media that would quickly wear out or block other valve types. Common long-tail use cases include:

  • Knife gate valves for wastewater and sludge: Standard applications in wastewater treatment plants and sewage systems, where the sharp gate cuts through fibres and solids.
  • Industrial knife gate valves for abrasive media: Essential in mining, cement plants, and pulp & paper industries for sandy, mineral, or fibrous flows.
  • Knife gate valves for chemical and corrosive media: Stainless steel versions (e.g. FB200-SSERW) provide resistance to acids, alkalis, and aggressive chemicals.
  • Knife gate valves for viscous media and slurry: Proven performance in agriculture and food processing for thick, solids-laden fluids.

What Defines a High-Quality Knife Gate Valve?

Beyond selecting the correct material, the following quality features should be considered:

  • Bidirectional sealing: A high-quality knife gate valve provides reliable shut-off in both flow directions, allowing greater flexibility during installation and system design.
  • Full, unobstructed bore: In the fully open position, the gate is completely outside the flow path, minimizing pressure loss and preventing material build-up.
  • Robust body & corrosion-resistant components: Whether epoxy-coated cast iron or stainless steel 1.4408, material selection must match the application. Stainless steel stems and gates significantly extend service life.

Important Application Note

Knife gate valves are designed primarily for full open or full closed operation. They should not be used for throttling or fine flow control. Operating the valve in a partially open position can cause vibration, cavitation, and accelerated wear of the gate and seat.

Your Advantage with FERGO

As a specialized provider of industrial valves, we deliver not only products but also expertise: 

  • Comprehensive Consultation: We assist in selecting between gray cast iron and stainless steel, the appropriate seal (EPDM, NBR, metal), and the correct nominal diameter.
  • High Availability: Many common slide gate valve models are available from stock.
  • Matching Accessories: Upon request, we supply all necessary seals and mounting parts. For other applications, we also offer pneumatically actuated slide gate valves.

Do you need a robust shut-off solution for difficult media? Contact us for a non-binding consultation or request a quote directly for your handwheel-operated slide gate valve.

Frequently Asked Questions – Knife Gate Valves

A knife gate valve (also called a knife gate or slide gate valve) uses a thin, flat gate with a sharpened leading edge that slides vertically through the flow path to open or close the valve. This sharp "knife" edge is what sets it apart from conventional gate valves:
  • Cuts through media – The knife-edged gate slices cleanly through slurry, sludge, fibrous materials, and media with a high solid content on closing, preventing the gate from jamming or becoming stuck
  • Self-cleaning seat – Many models feature an integrated scraper effect at the seat ring, which cleans the sealing surface as the gate closes, extending the service life of the seat elastomer even with abrasive media
  • Short face-to-face dimension – Knife gate valves are available in wafer (inter-flange) construction, giving them a very compact axial length compared to conventional gate valves – critical for retrofitting into existing pipelines
  • Full bore when open – The gate retracts fully out of the flow path when open, providing an unrestricted bore with minimal pressure drop
  • Vertical stem travel – The gate moves linearly up and down; a rising stem (visible position indication) or non-rising stem is used depending on available headroom
Because of these characteristics, knife gate valves are the preferred isolation valve for media that would clog, jam, or rapidly wear a standard ball valve, butterfly valve, or gate valve.
FERGO offers knife gate valves in 3 subcategories covering all standard actuation types, from manual operation to high-speed automated control:
  • Knife Gate Valves – Handwheel – Manual actuation via handwheel with rising or non-rising stem. Rising stem provides direct visual open/closed indication and ergonomic operation. Non-rising stem requires less headroom above the valve. Available in stainless steel (CF8M / 1.4408) and gray cast iron (GG25); uni- and bi-directional sealing; NBR, EPDM, or metal seat ring; DN50–DN600, PN10. The standard choice for manual isolation duties where automated operation is not required.
  • Pneumatic Knife Gate Valves – Double-acting pneumatic actuator for automated open/close control. Air supply 4–8 bar; fast switching times; suitable for remote operation via PLC or SCADA; ATEX-capable configurations available for use in hazardous areas. Stainless steel and GG25 bodies; DN50–DN600, PN10. Ideal for automated wastewater treatment plants, chemical dosing lines, and mining processes where manual operation is impractical.
  • Knife Gate Valves – Lever (Quick-close) – Manual actuation via a quick-close lever mechanism for fast, one-motion opening and closing. Designed for applications where rapid shut-off is required and a handwheel's multi-turn operation is too slow. Typically used at silo outlets, bulk material handling equipment, and emergency shut-off points. GG25 body; DN50–DN300; NBR or EPDM seat; PN10.
All FERGO knife gate valves are Made in EU and available from DN50 to DN600 in standard configurations; custom sizes on request.
FERGO knife gate valves are available in two body materials, each suited to different operating environments:

Stainless steel – CF8M / 1.4408 (AISI 316 / V4A):
  • Gate: SS316L (1.4404); Stem: SS303 (1.4305)
  • Excellent corrosion resistance against aggressive media, acids, alkalis, chlorinated water, and environments where rust contamination is unacceptable
  • Preferred for: food processing, pharmaceuticals, hygienic applications, chemical industry, drinking water, aggressive slurries
  • Required wherever the medium must not be contaminated by iron corrosion products
  • Higher material cost – justified by longer service life in corrosive environments
Gray cast iron – GG25:
  • Gate: SS304L (1.4306); Stem: SS303 (1.4305) – stainless wetted parts despite cast iron body
  • Good mechanical strength and dimensional stability; economical material cost
  • Preferred for: municipal wastewater treatment, paper and pulp industry, mining and minerals processing, agricultural irrigation, power generation cooling water
  • Not suitable for strongly acidic or alkaline media, seawater, or applications requiring full corrosion resistance
  • Lower acquisition cost – the standard choice for high-volume water/wastewater utility applications
Practical guideline: If the process fluid is corrosive, hygienic, or requires a clean material contact surface → stainless steel. If the fluid is neutral-to-mildly aggressive (municipal wastewater, cooling water, mining slurry) and cost is a key factor → GG25 with stainless steel wetted parts.
Knife gate valve performance in demanding media depends heavily on the correct seat elastomer and sealing construction. FERGO offers:

Seat elastomers:
  • NBR (Nitrile Butadiene Rubber) – General-purpose elastomer; good resistance to mineral oils, hydrocarbons, sewage, and neutral aqueous media; temperature range −10 °C to +90 °C. Standard choice for wastewater and municipal applications.
  • EPDM (Ethylene Propylene Diene Monomer) – Excellent resistance to steam, hot water, mild acids, alkalis, and ozone; not suitable for mineral oils or hydrocarbons; temperature range −40 °C to +120 °C. Preferred for chemical and food processing applications.
  • Metal seat – Hardened stainless steel seat for abrasive media where elastomers would rapidly wear; high-temperature applications above elastomer limits; and media containing coarse solids that would cut through soft seats. Bi-directional metal sealing is available for high-pressure or high-abrasion duties.
Sealing construction:
  • Uni-directional (single-sided) – Seals against pressure from one direction only; the standard and most cost-effective configuration; sufficient for the majority of isolation applications
  • Bi-directional (double-sided) – Seals against pressure from both directions; required for reversible flow lines, pump bypass circuits, and any installation where backpressure may act on the closed valve
Integrated scraper packing – Models with PTFE-Synt./NBR/PTFE-Synt. or PTFE-Synt./EPDM/PTFE-Synt. packing combine a self-cleaning scraper action at the gate entry point with the elastomer seat seal, significantly extending service life in media carrying fibres, pulp, or coarse particles.
Pneumatic knife gate valves are the right choice whenever:
  • The valve must be operated remotely or automatically from a control room or PLC
  • High cycle frequency makes manual operation impractical (e.g. dosing systems, automated filtration lines)
  • Fast response times are required – pneumatic double-acting actuators switch in seconds
  • Compressed air is already available on site (standard in most industrial plants)
  • ATEX-certified automation is needed for hazardous area classification
Key selection points:
  • Double-acting actuator – Air required for both opening and closing strokes; maximum force in both directions; the standard for knife gate valves where the gate weight and packing friction require positive actuation in both directions. Note: unlike ball or butterfly valves, spring-return (single-acting) is less common on knife gate valves due to the high actuation force required for large bore sizes.
  • Control: Pair with a 5/2-way NAMUR solenoid valve (24 V DC) for direct PLC control. Add a Switchmaster limit switch box (IP67 / ATEX) for OPEN/CLOSED position feedback to the control system.
  • Actuator sizing: Knife gate valves require higher actuation force than equivalent ball or butterfly valves – particularly with fibrous media where the gate must cut through material on closing. Always confirm the actuator torque/force rating against the valve's required operating force.
FERGO supplies pneumatic knife gate valves as factory-assembled, tested units ready for installation.
The stem design of a handwheel knife gate valve determines how the stem behaves during operation and what the installation requirements are:

Rising stem (tige montante):
  • The stem moves upward as the valve opens and downward as it closes – the stem position directly indicates the gate position at all times
  • Advantage: Immediate visual position confirmation without any additional indicator; easy to see whether the valve is open or closed from a distance
  • Requirement: Adequate headroom above the valve equal to at least the full stroke length of the gate (i.e. one full bore diameter above the handwheel)
  • Standard choice when headroom is available and visual position indication is a priority
Non-rising stem:
  • The stem rotates in place and does not extend upward – the valve occupies a fixed height envelope regardless of gate position
  • Advantage: Minimal installation height; suitable for installations in confined spaces, low-clearance ceilings, or underground chambers
  • Requirement: A separate position indicator (e.g. visual indicator disc on the handwheel, or an electronic limit switch) should be used to confirm valve status, as the gate position is not externally visible
  • Preferred in underground installations, valve pits, and compact mechanical rooms
Knife gate valves are specifically engineered for media that conventional valves cannot handle reliably. Typical industries and applications:
  • Municipal and industrial wastewater treatment – Isolation of sludge lines, raw sewage channels, aerated grit chambers, sludge thickeners; GG25 body with NBR or EPDM seat; the most common application globally
  • Paper and pulp industry – Control of wood pulp, paper stock, black liquor, and fibrous slurries; the sharp gate edge cuts through fibres on closing; scraper packing prevents fibre build-up at the gland
  • Mining and minerals processing – Isolation of ore slurries, tailings, mineral concentrates, abrasive slurries; metal seat for wear resistance; stainless steel for corrosive mine water
  • Chemical industry – Isolation and on/off control of aggressive liquids, chemical slurries, and process fluids; stainless steel 1.4408 body and gate; EPDM or metal seat depending on chemical compatibility
  • Food and beverage / agriculture – Handling of grain, starch slurries, vegetable mash, fermentation residues, and agricultural waste; stainless steel body for hygiene; EPDM seat for steam-in-place cleaning compatibility
  • Power generation – Isolation of cooling water circuits, ash slurry transport, and coal preparation plant drainage; GG25 body with large nominal sizes up to DN600
  • Silo and bulk material handling – Quick-close lever models for direct mounting beneath silo outlets, hoppers, and conveying equipment; fast one-motion closing to stop bulk material flow
All three are isolation valves, but they are engineered for fundamentally different media types and installation conditions:

Choose a knife gate valve when:
  • Media contains solids, fibres, slurry, sludge, or suspended particles that would clog or damage other valve types
  • Self-cleaning gate action (scraper effect) is needed to prevent solids build-up at the seat
  • Large nominal sizes (DN50–DN600) are required at low pressure (PN10)
  • Compact face-to-face (wafer construction) is needed for retrofitting into existing pipe systems
  • Cost efficiency is important at large bore sizes handling non-clean media
Choose a gate valve (wedge gate) when:
  • Media is clean (drinking water, gas, steam, clean process fluids)
  • Higher pressure ratings are required (PN16–PN40 or ANSI Class 150–300)
  • DVGW certification for drinking water or gas is required
  • Metal-to-metal sealing for high-temperature or high-pressure steam service is needed
Choose a butterfly valve when:
  • Media is clean to moderately loaded (water, HVAC, air handling, dilute slurries)
  • Very large nominal sizes (DN200–DN1200) are needed at lowest possible cost and weight
  • Throttling (partial flow control) as well as isolation is required
  • The disc obstruction in the flow path is acceptable (butterfly valves are not full bore)