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Knife Gate Valves Handwheel
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Knife Gate Valves Lever
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FM200 Knife-gate valve DN 100 EPDM cast iron double-acting Pneumatic actuator
Product number
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270-1008-12
Wafer-type knife gate valve/flat knife gate valve DN 100 PN10, single-seated design, seat ring made of EPDM, body made of grey cast iron (GG25), knife gate valve plate made of stainless steel SS304L (1.4306), stem made of stainless steel SS303 (1.4305) with pneumatic double-acting actuator
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN100 - 4'' inch
Design :
sealing on one side
Seat:
EPDM
Body:
Grey Cast Iron
Actuation :
Pneumatic Actuator
Price
€437.18
€520.24 incl. VAT
Delivery Time:
in stock
Available:
In Stock
FB700 Knife-gate valve DN 150 PN10 NBR cast iron double-acting pneumatic actuator
Product number
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270-3011-14
Wafer type knife gate valve DN 150 PN10Design double seated, seat ring U-bolt seal NBR 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./NBR/PTFE-Synt. with pneumatic double acting
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN150 - 6'' inch
Seat:
NBR
Design :
sealing on both sides
Body:
Grey Cast Iron
Actuation :
Pneumatic Actuator
Price
€656.21
€780.89 incl. VAT
Delivery Time:
in stock
Available:
In Stock
FB700 Knife-gate valve DN 100 NBR cast iron double-acting pneumatic actuator
Product number
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270-3011-12
Knife gate valve DN 100 PN10 pneumaticDouble poppet design, seat ring U-bolt seal NBR 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./NBR/PTFE-Synt. with pneumatic double-acting
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN100 - 4'' inch
Seat:
NBR
Design :
sealing on both sides
Body:
Grey Cast Iron
Actuation :
Pneumatic Actuator
Price
€484.85
€576.97 incl. VAT
Delivery Time:
in stock
Available:
In Stock
FB700 Knife-gate valve DN 200 NBR cast iron double-acting pneumatic actuator
Product number
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270-3011-16
Wafer type knife gate valve DN 200 PN10Design bi-directional, seat ring U-bolt seal NBR 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./NBR/PTFE-Synt. with pneumatic double-acting
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN200 - 8'' inch
Seat:
NBR
Design :
sealing on both sides
Body:
Grey Cast Iron
Actuation :
Pneumatic Actuator
Price
€973.73
€1,158.74 incl. VAT
Delivery Time:
in stock
Available:
In Stock
FB700 Knife-gate valve DN 200 EPDM cast iron double-acting pneumatic actuator
Product number
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270-3010-16
Wafer Gate Valve DN 200 PN10Design bi-directional, seat ring U-bolt seal NBR 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./NBR/PTFE-Synt. - double acting pneumatic actuator
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN200 - 8'' inch
Seat:
EPDM
Design :
sealing on both sides
Body:
Grey Cast Iron
Actuation :
Pneumatic Actuator
Price
€973.73
€1,158.74 incl. VAT
Delivery Time:
in stock
Available:
In Stock
FM200 Knife-gate valve DN 100 NBR cast iron double-acting pneumatic actuator
Product number
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270-1011-12
Wafer type gate valve DN 100 PN10 with actuatorDesign single-seated, 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) with pneumatic double-acting
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN100 - 4'' inch
Design :
sealing on one side
Seat:
NBR
Body:
Grey Cast Iron
Actuation :
Pneumatic Actuator
Price
€437.18
€520.24 incl. VAT
Delivery Time:
in stock
Available:
In Stock
FM200 Knife gate valve DN 100 EPDM stainless-steel Pneumatic
Product number
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270-1006-12
Knife gate valve pneumatic DN 50 PN10 Unidirectional design, Wafer 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, with pneumatic double-acting actuator
Slider plate:
Stainless steel SS304L (1.4306)
Slider plate:
Stainless steel SS316L (1.4404)
Nominal width :
DN100 - 4'' inch
Design :
sealing on one side
Seat:
EPDM
Body:
Stainless Steel
Price
€736.85
€876.85 incl. VAT
Delivery Time:
in stock
Available:
In Stock
FB700 Knife-gate valve DN 125 NBR cast iron double-acting pneumatic actuator
Product number
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270-3011-13
Knife gate valve DN 125 PN10 made of GG25Design bi-directional, seat ring U-bolt seal NBR 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./NBR/PTFE-Synt. with pneumatic double-acting
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN125 - 5'' inch
Seat:
NBR
Design :
sealing on both sides
Body:
Grey Cast Iron
Actuation :
Pneumatic Actuator
Price
€579.60
€689.72 incl. VAT
Delivery Time:
in stock
Available:
In Stock
FB700 Knife-gate valve DN 65 EPDM cast iron double-acting pneumatic actuator
Product number
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270-3010-10
Knife Gate Valve - Flat Gate Valve DN 65 PN10Design bi-directional | seat ring U-bolt seal NBR with profile steel core reinforcement, body made of grey cast iron (GG25), gate & stem made of stainless steel, plate guide with integrated scraping effect, packing PTFE-Synt./NBR/PTFE-Synt. | double-acting pneumatic actuator
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN65 - 2 1/2'' inch
Seat:
EPDM
Design :
sealing on both sides
Body:
Grey Cast Iron
Actuation :
Pneumatic Actuator
Price
€420.34
€500.20 incl. VAT
Delivery Time:
in stock
Available:
In Stock
FM200 Knife-gate valve DN 150 NBR cast iron double-acting pneumatic actuator
Product number
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270-1011-14
Wafer type knife gate valve/flat knife gate valve DN 150 PN10Single-seated design, seat ring made of NBR, body made of grey cast iron (GG25), gate made of stainless steel SS304L (1.4306), stem made of stainless steel SS303 (1.4305) with pneumatic double acting
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN150 - 6'' inch
Design :
sealing on one side
Seat:
NBR
Body:
Grey Cast Iron
Actuation :
Pneumatic Actuator
Price
€608.26
€723.83 incl. VAT
Delivery Time:
in stock
Available:
In Stock
FM200 Knife gate valve DN 150 metallic cast iron double-acting pneumatic actuator
Product number
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270-1003-14
Knife Gate Valve DN 150 PN10Design single-seated, seat ring made of metal, body made of grey cast iron (GG25), gate made of stainless steel SS304L (1.4306), stem made of stainless steel SS303 (1.4305) with pneumatic double-acting actuator
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN150 - 6'' inch
Design :
sealing on one side
Seat:
Metallic
Body:
Grey Cast Iron
Actuation :
Pneumatic Actuator
Price
€578.69
€688.64 incl. VAT
Delivery Time:
in stock
Available:
In Stock
FM200 Knife-gate valve DN 200 EPDM cast iron double-acting pneumatic actuator
Product number
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270-1008-16
Knife Gate Valve DN 200 PN10Design single-seated, 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) with pneumatic double-acting actuator
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN200 - 8'' inch
Design :
sealing on one side
Seat:
EPDM
Body:
Grey Cast Iron
Actuation :
Pneumatic Actuator
Price
€881.66
€1,049.18 incl. VAT
Delivery Time:
in stock
Available:
In Stock
FM200 Knife-gate valve DN 80 EPDM Cast iron double-acting pneumatic actuator
Product number
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270-1008-11
Knife gate valve DN 80 PN10 pneumatic actuatorSingle-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) with pneumatic double-acting actuator
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN80 3'' inch
Design :
sealing on one side
Seat:
EPDM
Body:
Grey Cast Iron
Actuation :
Pneumatic Actuator
Price
€410.78
€488.83 incl. VAT
Delivery Time:
in stock
Available:
In Stock
FB700 Knife-gate valve DN 150 EPDM cast iron double-acting pneumatic actuator
Product number
Copy to clipboard
270-3010-14
Wafer type knife gate valve DN 150 PN10Design bi-directional | seat ring U-bolt seal NBR 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./NBR/PTFE-Synt. | double-acting pneumatic actuator
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN150 - 6'' inch
Seat:
EPDM
Design :
sealing on both sides
Body:
Grey Cast Iron
Actuation :
Pneumatic Actuator
Price
€656.21
€780.89 incl. VAT
Delivery Time:
in stock
Available:
In Stock
FM200 Knife-gate valve DN 125 EPDM stainless-steel pneumatic
Product number
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270-1006-13
Knife gate valve pneumatic DN 125 PN10 Unidirectional design, Wafer 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, with pneumatic double-acting actuator
Slider plate:
Stainless steel SS304L (1.4306)
Slider plate:
Stainless steel SS316L (1.4404)
Nominal width :
DN125 - 5'' inch
Design :
sealing on one side
Seat:
EPDM
Body:
Stainless Steel
Price
€869.98
€1,035.28 incl. VAT
Delivery Time:
in stock
Available:
In Stock
FM200 Knife-gate valve DN 125 EPDM double-acting cast iron Pneumatic actuator
Product number
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270-1008-13
Wafer-type knife gate valve/flat knife gate valve DN 125 PN10, single-seated design, seat ring made of EPDM, body made of grey cast iron (GG25), valve plate made of stainless steel SS304L (1.4306), stem made of stainless steel SS303 (1.4305) with pneumatic double-acting actuator
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN125 - 5'' inch
Design :
sealing on one side
Seat:
EPDM
Body:
Grey Cast Iron
Actuation :
Pneumatic Actuator
Price
€538.56
€640.89 incl. VAT
Delivery Time:
in stock
Available:
In Stock
FM200 Knife-gate valve DN 125 NBR cast iron double-acting Pneumatic actuator
Product number
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270-1011-13
Wafer-type knife gate valve/flat knife gate valve DN 125 PN10, single-seated design, seat ring made of NBR, body made of grey cast iron (GG25), valve plate made of stainless steel SS304L (1.4306), stem made of stainless steel SS303 (1.4305) with pneumatic double acting
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN125 - 5'' inch
Design :
sealing on one side
Seat:
NBR
Body:
Grey Cast Iron
Actuation :
Pneumatic Actuator
Price
€538.56
€640.89 incl. VAT
Delivery Time:
in stock
Available:
In Stock
FB700 Knife-gate valve DN 250 NBR cast iron double-acting pneumatic actuator
Product number
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270-3111-18
Flanged knife gate valve DN 250 PN10Design double seated, seat ring made of NBR 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./NBR/PTFE-Synt. with pneumatic double acting
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN250 - 10'' inch
Seat:
NBR
Design :
sealing on both sides
Body:
Grey Cast Iron
Actuation :
Pneumatic Actuator
Price
€1,421.28
€1,691.32 incl. VAT
Delivery Time:
in stock
Available:
In Stock
FB700 Knife-gate valve DN 300 PN10 NBR cast iron double-acting pneumatic actuator
Product number
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270-3011-20
Knife gate valve DN 300 PN10Design bi-directional, seat ring U-bolt seal NBR 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./NBR/PTFE-Synt. with pneumatic double-acting
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN300 - 12'' inch
Seat:
NBR
Design :
sealing on both sides
Body:
Grey Cast Iron
Actuation :
Pneumatic Actuator
Price
€1,817.42
€2,162.73 incl. VAT
Delivery Time:
in stock
Available:
In Stock
FM200 Knife gate valve DN 80 metal seated double-acting Pneumatic actuator
Product number
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270-1003-11
Wafer type knife gate valve DN 80 PN10Single-seated design, seat ring made of metal, body made of grey cast iron (GG25), valve plate made of stainless steel SS304L (1.4306), stem made of stainless steel SS303 (1.4305) with pneumatic double-acting actuator
Slider plate:
Stainless steel SS304L (1.4306)
Nominal width :
DN80 3'' inch
Design :
sealing on one side
Seat:
Metallic
Body:
Grey Cast Iron
Actuation :
Pneumatic Actuator
Price
€393.89
€468.73 incl. VAT
Delivery Time:
in stock
Available:
In Stock
Our Product Range: From Standard to High-Performance Slide Gate Valves
Our portfolio includes various series that differ in tightness, material, and construction details to meet every industrial requirement profile.
Product Series / Type |
Ideal Application & Media |
Technical Specifications & Materials |
Special Advantages & FERGO Expertise |
|---|---|---|---|
|
FM200 Series (single-sealing) Economical • Standard |
Bulk materials, powders, granular media, wastewater, sludges. Where a single seal is sufficient. |
Body: Gray cast iron (GG25) or Stainless steel CF8M. |
|
|
FB700 Series (double-sealing) High-tightness • For liquids |
Liquids, chemicals, aggressive media, process water. Anywhere absolute, double-sided tightness is required. |
Body: Gray cast iron (GG25). |
|
|
Stainless Steel Versions Corrosion-resistant • Hygienic |
Aggressive chemicals, acids, alkalis, foodstuffs, pharmaceutical products, seawater. Hygiene-critical processes (CIP/SIP). |
Body: Stainless steel CF8M (1.4408). |
|
The Actuator: Why Pneumatic Operation Is the First Choice
A pneumatic knife gate valve stands out primarily because of its actuation method. Compared to electric or manual operation, compressed air offers decisive advantages in industrial environments:
- High switching force and speed: Pneumatic cylinders generate significant force, allowing the valve to operate reliably even when the gate is stuck or under pressure. Switching times are extremely short.
- Simple and robust control: Integration into existing compressed air networks and control systems (PLC via solenoid valve) is straightforward. Pneumatic actuators are low-maintenance and resistant to harsh operating conditions.
- Safety in hazardous areas: Pneumatic actuators do not generate sparks and are therefore the preferred—and often mandatory—solution for explosion-risk areas (ATEX). Fully ATEX-certified valve assemblies are available on request.
- Operational reliability during power failure: Single-acting actuators with spring return allow defined safety positions (“fail-safe”) to be achieved in the event of a power or air supply interruption.
As standard, FERGO supplies pneumatic knife gate valves with double-acting cylinders for controlled movement in both directions. On request, valves can be equipped with limit switches or magnetic proximity sensors for position feedback to your control room.
Material Selection: Cast Iron or Stainless Steel?
Choosing the right body material is one of the most critical decisions and depends primarily on the conveyed medium.
- Cast iron knife gate valves (GG25): A cost-effective and extremely robust standard solution for the majority of industrial applications. Suitable for water, wastewater, many chemicals, bulk solids, and non-corrosive media. Proven design with excellent value for money.
- Stainless steel knife gate valves (1.4408): The preferred choice for aggressive, corrosive, or hygienically demanding media. Ideal for chemical processing, food production, or marine environments. For critical applications, EN 10204 3.1 material certificates are available upon request.
The Seal Makes the Difference: NBR, EPDM, or Metal?
The seat ring is the primary sealing element. Its chemical resistance must match the process medium:
- NBR (nitrile rubber): Good all-round performance with resistance to oils, greases, and many hydrocarbons.
- EPDM: Excellent suitability for hot water, steam (up to approx. 120 °C), alkalis, and polar chemicals.
- Metal seat: Designed for extreme temperatures, abrasive media, or high-pressure applications where elastomer seals reach their limits.
Your Advantage with FERGO: Technical Expertise and Fast Availability
- Expert technical consulting: Our engineering team supports you in selecting the appropriate sealing design (single or bidirectional), the right material, and the correct sizing of the pneumatic actuator.
- Complete valve assemblies: Upon request, we supply not only the knife gate valve but the fully assembled unit, including pneumatic actuator, solenoid valve, air preparation units, and pressure regulators – pre-mounted and function-tested.
- Extensive stock availability: Many of our pneumatic knife gate valves in standard sizes and configurations are available from stock and ready for rapid delivery.
Are you planning a new project or replacing an existing valve? Contact us for a non-binding technical consultation or request a quotation for your pneumatic knife gate valve directly.
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
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.
FERGO knife gate valves are available in two body materials, each suited to different operating environments:
Stainless steel – CF8M / 1.4408 (AISI 316 / V4A):
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
- 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
Knife gate valve performance in demanding media depends heavily on the correct seat elastomer and sealing construction. FERGO offers:
Seat elastomers:
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.
- 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
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
- 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.
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):
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
- 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:
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
- 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
- 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)