Wey Valve

What Wey Valve does

Wey Valve, a brand of the privately held Swiss company Sistag AG, manufactures industrial knife gate valves, butterfly and check valves, and houseless water control gates used in severe-service isolation and flow-control applications. Founded in 1956 by Joseph Wey, who patented the original bidirectional sealing system that remains the company's core technology, Wey has supplied over 1 million valves across more than 100 countries and operates production facilities in Eschenbach, Switzerland (headquarters), Shannon, USA, and a subsidiary in Germany (Sistag GmbH). The product portfolio spans nine knife gate valve series (MF, MG, VN, VL, VS, VK, HD, W, and MH) covering nominal sizes from DN 50 to DN 2000, pressures up to 100 bar, temperatures from cryogenic to 500°C, and a specialty SpeedWey HSI high-speed isolation valve that closes in 23 milliseconds for explosion protection.

The company's competitive position rests on the Original Wey Design — a patented combination of a resilient round-cord seal with metallic gate guides that delivers absolute bidirectional seat-tightness and atmosphere-sealing, plus the unusual ability to repack valves in-service under full pressure without removal or plant shutdown. Product differentiation is further supported by 65+ years of accumulated application engineering across mining (e.g., 10,000+ valves in Canadian oil sands, 300+ at Çöpler Gold Mine), municipal and industrial wastewater treatment (700+ of Switzerland's 800 WWTPs, ARA Basel's 700+ valve expansion, Henriksdal in Stockholm), paper and pulp, chemical/petrochemical, oil and gas, and emerging segments including biogas, seawater heat pumps, food (Knife Cheese Valve), and aerospace engine testing.

Wey generates revenue through one-time capital equipment sales of custom-configured valves and aftermarket spare parts and maintenance support. Pricing is quote-based and varies by valve series, nominal size, material, pressure rating, and actuator type. Go-to-market combines direct enterprise field sales from the Swiss HQ (RFQ intake via phone and email) with a network of 100+ distribution partners across Europe, the Americas, Asia-Pacific, and Australia, and wholly-owned subsidiaries serving the US (Wey Valve Inc.) and German markets (Sistag GmbH). The company maintains ISO 9001:2015, iQNet, SIL 3, PED Module H, ATEX, DVGW/SVGW, and TR CU certifications, and exhibits at major industry trade shows such as IFAT Munich. Headcount is reported at 11-50 employees, and revenue is not publicly disclosed.

Name

Wey Valve

Legal name

Sistag AG

Website

https://weyvalve.com

Company type

Private

Founded year

1956

Operating status

Operating

Headcount range

11–50 employees

Short description

Wey Valve, a Swiss brand of Sistag AG, manufactures industrial knife gate valves, butterfly valves, and water control gates using its patented 1956 Original Wey Design sealing system. It serves severe-service applications in mining, wastewater, paper, chemical, oil & gas, and emerging verticals across 100+ countries.

Ownership category

akta.pro rank

Product category

Industrial Valves and Flow Control Equipment

NAICS

Industrial Valve Manufacturing (332911), Metal Valve Manufacturing (33291)

SIC

Special Industry Machinery (No Metalworking Machinery) (3550)

akta.pro primary industry

Valves & Cartridge Valves (Directional, Pressure, Flow Control) (IMAHAGAE)

akta.pro secondary industry

Seals, Gaskets & Fluid Connectors (O-rings, packings, rotary seals, quick couplers) (IMAHAGAI)

Keywords

• Industrial knife gate valves
• Butterfly and check valves
• Water control gates
• Slurry and mining valves
• Wastewater treatment valves

Headquarters

HQ city

Shannon

HQ country

United States

HQ region

North America

Offices2 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Operations, Supply Chain, Technology or R&D, Personnel, Marketing or Sales, Infrastructure

Revenue model

1. Industrial Valve Sales: Wey Valve generates revenue through the manufacture and sale of industrial knife gate valves, butterfly valves, check valves, and water control gates. Products are sold as one-time capital equipment to industrial customers across mining, wastewater, paper, chemical, oil & gas, and other sectors. The company also generates revenue from after-market services including repair, spare parts, and maintenance support.

Go-to-market motion1 record

Distribution channels2 records

Marketing channels6 records

Core offering

Wey Valve, a brand of the Swiss company Sistag AG, designs and manufactures industrial knife gate valves, butterfly and check valves, and houseless water control gates. Its products are engineered around the patented Original Wey Design sealing system (1956), providing bidirectional seat-tightness, atmosphere-tightness, the ability to repack valves in-service under full pressure, and self-cleaning handling of solids-laden media for wastewater, mining, paper, chemical, oil & gas, and biogas applications.

Product overview

Wey Valve, a brand of Sistag AG based in Switzerland, manufactures industrial knife gate valves, butterfly and check valves, and houseless water control gates. The product portfolio centers on the patented Original Wey Design (1956) sealing system, which provides bidirectional seat sealing and repackability under full pressure. The knife gate valve range spans 9 distinct series: MF (universal, 50–2000 mm), MG (16 bar rated, 50–800 mm), VN (economical intermediate-flange, 50–1400 mm), VL (threaded flange stainless steel, 50–800 mm), VS (MSS-SP81 stainless steel, 50–900 mm), VK (square-flange, 200–1000 mm), HD (high-pressure to 100 bar, 80–400 mm), W (heavy duty severe service, 2–36 inches), and MH (mining heavy duty to 25 bar, 100–400 mm). The butterfly valve line includes TW and TL series (DN 25–1600) with DVGW/SVGW drinking water certification. Specialty products include the SpeedWey high-speed isolation valve (HSI) for explosion protection and houseless sluice gates for water management. Products serve industries including mining, paper/pulp, wastewater treatment, oil and gas, chemical/petrochemical, food/beverage, and biogas/renewable energy.

Differentiator

Problem solved

Functional benefit

Brands

• Original Wey Design: The patented 1956 sealing system that forms the core technology of all Wey knife gate valves, combining a resilient seal with metallic gate guides and support.

Products and services

• MF Series Knife Gate Valve A universally applicable, center-flanged knife gate valve with robust and modular construction, covering nominal sizes 50–2000 mm and pressures up to 16 bar in cast iron, spheroidal graphite iron, with handwheel, bevel gear, pneumatic, electric, and hydraulic actuator options, for industrial flow isolation across water, mining, paper, and chemical service.
• MG Series Knife Gate Valve Universal knife gate valve rated for pressures up to 16 bar at the same face-to-face length as standard 10 bar valves, available in nominal sizes 50–800 mm in stainless steel and spheroidal graphite iron and featuring the Original Wey Design sealing system, for general-purpose industrial isolation.
• VN Series Knife Gate Valve Intermediate-flanged knife gate valve in an economical design covering the most common market requirements, with bidirectional absolute seat sealing and body sealing against the atmosphere, available in nominal sizes 50–1400 mm and pressures 0–10 bar in cast iron, stainless steel, and special materials, for cost-sensitive water, paper, and wastewater applications.
• VL Series Threaded Flange Knife Gate Valve Optimized threaded flange knife gate valve combining cost-saving design with maximum performance, standard in stainless steel and intended for corrosive applications with 100% bidirectional leak-free design at nominal sizes 50–800 mm and pressures 0–16 bar.
• VS Series Knife Gate Valve Stainless steel knife gate valve series in MSS-SP81 design for corrosive applications, nominal sizes 50–900 mm, ANSI Class 150 flange pattern, often equipped with PTFE coatings and ATEX certification for use in explosive atmospheres.
• VK Series Square/Rectangular Knife Gate Valve Square-flange knife gate valve for rectangular or square flange connections requiring absolute tightness, sizes 200–1000 mm at 0–2.5 bar in cast iron and stainless steel, suitable for silo and hopper outlet isolation.
• HD Series High-Pressure Knife Gate Valve High-pressure knife gate valve rated up to 100 bar, with an automatic sealing effect generated by medium pressure in the flow passage and a special hood construction allowing flushing of solids-containing media while remaining bubble-tight to the atmosphere, sizes 80–400 mm, intended for mining, oil & gas, and high-pressure slurry isolation.
• W Series Heavy Duty Knife Gate Valve Severe-service, high-performance heavy-duty knife gate valve with the highest flexibility in nominal size, material, and pressure range, featuring a double-flange design with improved body seal, mechanical gate support, and second transverse seal for absolute tightness at pressures up to 50 bar and temperatures up to 220°C, sizes 2–36 inches.
• MH Series Mining Knife Gate Valve Heavy-duty knife gate valve designed specifically for mining applications handling solids-containing media, with sizes 100–400 mm and pressures up to 25 bar, featuring double transverse seals in heavy execution with two scrapers, a Super Duplex stainless-steel gate and body, and Stellite coating on the gate plate and flow passage for additional hardness.
• SpeedWey High-Speed Isolation Valve (HSI) High-speed isolation knife gate valve that closes automatically in as fast as 23 milliseconds upon detecting an explosion, preventing explosion propagation through pipelines and protecting personnel and equipment, with an available hygienic version featuring a PTFE liner for pharmaceutical and food applications.
• Butterfly and Check Valves (TW / TL series) Centric butterfly valves and check valves for flow control and backflow prevention, including the TW and TL series, DN 25–1600 with DVGW/SVGW certification for drinking water and gas applications, and pneumatic, electric, and manual actuator options.
• Sluice Gates (Normschütz) and Water Control Gates Standard and custom-designed houseless sluice gates (Normschütz) for water management, flood protection, and pumping-station applications, available up to 4 m clear width with manual or motorized actuators and water column ratings to 5.5 m, including round profiles and reinforced variants.
• Wey Knife Cheese Valve Specialized knife gate valve developed for the food industry, combining Swiss manufacturing tradition with engineering customization for application-specific sanitary and food-grade service.
• After-Sales Service, Spare Parts, and Maintenance Support After-sales service offering for installed Wey valves, including repair, spare parts, and preventive and corrective maintenance support, supported by online video tutorials on repacking, actuator mounting, and leak repair, and downloadable operation and maintenance documentation, for industrial valve customers seeking to maximize in-service valve life.

Quantifiable outcome

• Absolute bidirectional leak-tightness (0 leak rate) achieved in both seat-sealing and atmosphere-sealing across the full pressure range
• +5 more outcomes

Named customers13 records

Segments7 records

Ideal customer profiles4 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration2 records

Feature5 records

Partnerships

Four partnerships are on record, tiered core and minor.

• SycomorecoreChannel Partner/ Reseller/ DistributorSycomore is a Wey distribution partner that executed the O·PARK1 bio-waste treatment project in Hong Kong together with sister companies Naskeo Environnement and Ter'Green. Sycomore functions as the Wey brand ambassador for the project, coordinating system design and valve integration.
• Naskeo EnvironnementminorImplementation/ SI/ Consulting PartnerSister company to Sycomore, involved as a partner in the O·PARK1 project execution. Part of the Sycomore group of companies serving as Wey's implementation partners for the Hong Kong bio-waste project.
• Ter'GreenminorImplementation/ SI/ Consulting PartnerSister company to Sycomore, involved as a partner in the O·PARK1 project execution. Part of the Sycomore group of companies serving as Wey's implementation partners for the Hong Kong bio-waste project.
• EIP Enviro Level Controls Pvt LtdminorChannel Partner/ Reseller/ DistributorEIP Enviro Level Controls Pvt Ltd serves as a Wey distribution partner in India, coordinating the delivery of large valves such as the MFH DN 1600 for steel manufacturer applications.

Scale indicators8 records

Recent moves6 records

Expansion highlights6 records

Peers

• Velan Inc.

Direct peers

• Orbinox: Spanish-headquartered global manufacturer of knife gate valves, penstocks, and specialty valves for wastewater, mining, pulp & paper, and power. Orbinox is the closest direct competitor to Wey, offering an overlapping product range including unidirectional and bidirectional sealing knife gate valves serving the same heavy-industry end markets.
• DeZURIK (Larsson International): US-based manufacturer of knife gate valves, butterfly valves, and plug valves for water/wastewater, pulp & paper, mining, and power generation. DeZURIK's KGN-R and Larsson knife gate valve lines compete head-to-head with Weynless MF, MG, and W series in North American municipal and industrial markets.
• Fabri-Valve: US manufacturer specializing in knife gate valves for the pulp & paper, mining, wastewater, and chemical industries. Comparable product portfolio (unidirectional/bidirectional sealing, pneumatic and electric actuation) and shared emphasis on severe-service slurry and fibrous media handling.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat6 records

Key risks1 record

Key highlights6 records

Customer concentration

• YouTubeyoutube.com/channel/UCN9w1Lv8DSIcEkexx--NSCg
• Facebookfacebook.com/weyvalve
• LinkedInlinkedin.com/company/23307943
• Instagraminstagram.com/weyvalve

Compliance9 records

Revenue estimate

Valuation estimate

Number of profiles

Subsidiaries2 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Wey Valve