Knife gate valve manufacturers in USA
SVR Global manufactures knife gate valves for isolation service in slurry, solids laden, and fibrous media unidirectional and bidirectional, with resilient or metal seats, and manual, pneumatic, electric, or hydraulic actuation. Bodies are available in cast iron, carbon steel, and stainless steel, built to MSS SP-81 and ASME B16.34, with hardfaced or ceramic coated blade options for abrasive service across mining, pulp and paper, power generation, and water/wastewater applications in US.
What Is a Knife Gate Valve?
A knife gate valve is a linear motion valve with a sharp edged blade (gate) that moves perpendicular to the flow path. The blade's edge cuts through suspended solids, fibrous material, or slurry as it closes, allowing the valve to seal in media that would jam or wear out a standard gate valve. It's built for full open/full closed isolation service, not throttling.
Types of Knife Gate valve:
Bidirectional Knife Gate Valve
Flanged Knife Gate Valve
Slurry Knife Gate Valve
Through Conduit Knife Gate Valve
Unidirectional Knife Gate Valve
Unidirectional vs Bidirectional Knife Gate Valves
Type | Sealing Direction | Typical Use |
Unidirectional | Seals against pressure from one side only | Standard isolation where flow direction is fixed and known |
Bidirectional | Seals against pressure from either side | Systems where flow direction can reverse, or where the valve may see backflow |
Body Materials:
Cast iron / ductile iron: standard for general slurry and wastewater service where the media isn't strongly corrosive
Carbon steel: used where higher pressure ratings or structural strength are needed
Stainless steel (304, 316): specified for corrosive media or where product purity/cleanliness matters
Weldable alloys: for custom or higher-alloy applications outside the standard material range
Seat Types:
Resilient (elastomer) seat: EPDM, Buna-N, or Viton sealing surface drip tight at moderate pressure, most common for slurry and wastewater service.
Metal seat: machined metal to metal seal for higher temperature or higher-pressure service, with less shutoff tightness than a resilient seat.
Blade Materials and Coatings:
The blade sees the most direct wear from abrasive media, so its material and surface treatment drive service life:
304 / 316 stainless steel blade: standard corrosion resistance for general slurry service
Duplex or higher alloy stainless: for more aggressive corrosive or high chloride media
Hardfaced or ceramic coated blade: applied for highly abrasive slurries (mining tailings, fly ash) to extend service life well beyond an uncoated blade
Packing and Sealing Systems:
Compression packing: traditional packing rings compressed around the blade to control leakage along the stem/blade path requires periodic adjustment as it wears
Live loaded packing: uses spring tension to maintain consistent compression on the packing automatically, reducing how often manual adjustment is needed
Double O-ring / lip seal systems: used on higher performance valves for tighter control of leakage past the blade
Standards and Certifications:
MSS SP-81 - the primary industry standard covering knife gate valve design, dimensions, and pressure-temperature ratings
API 6D - referenced where knife gate valves are used in pipeline isolation service
ASME B16.34 - pressure temperature rating reference for the body materials used
AWWA M72 - a manual of water supply practices specifically addressing knife gate valve selection and operation in waterworks service
Testing and Quality Control:
Hydrostatic and seat leakage testing: every valve tested to confirm body integrity and shutoff performance before shipment
Material Test Reports (MTRs): heat traceable documentation for body, blade, and seat materials
Third-party inspection: independent verification of dimensional and material compliance, typically specified for larger orders or documented conformance requirements
Industries and Applications:
Mining and mineral processing - abrasive slurry, tailings, and hydrocyclone isolation
Pulp and paper - pulp stock and fibrous media isolation
Water and wastewater treatment - sludge, biosolids, and solids laden process line isolation
Power generation - fly ash and bottom ash handling systems
Chemical processing - corrosive slurry and solids laden line isolation
