Slurry Knife Gate Valve

SVR Global offers knife gate valves that are specifically designed for use in applications that have to deal with abrasive and highly solidified fluid products in sectors like mining, mineral processing, power generation, and pulp & paper. 

Our valves have gate knives, wear resistant seats, and rugged valve bodies that can be used to block the flow in slurry lines.

What is a Slurry Knife Gate Valve?

Slurry knife gate valves are single direction or double direction shut off valves that have a sharp blade as a gate that cuts the thick and tough material as it shuts off.

How Does a Slurry Knife Gate Valve Work?

The valve operates through a stem connected to a handwheel, gearbox, or actuator:

• Open position: The gate retracts fully into the valve bonnet, leaving a straight through bore for unrestricted slurry flow.

• Closed position: The gate lowers through the flow stream, cutting through suspended solids and sealing against the resilient seat.

The knife edge design allows the valve to close even when solids have settled at the bottom of the line, a condition that would jam a conventional gate valve.

Key Construction Features for Slurry Service:

• Hardened Gate Blade: Made from stainless steel or coated with abrasion resistant alloy to withstand solid cutting wear.

• Resilient Seat Construction: Elastomeric or metallic seats that retain shut off despite wear to the blade over multiple operations.

• Bidirectional Sealing: Most valves provide bidirectional sealing, suitable for use in slurry lines with reverse flow or backflow.

• Enclosed / Open Bonnets: Ensures the gate track is free from accumulation of solids.

• Packing Gland and Flushing Port: Used for introducing flushing liquid into the valve to prevent packing of solids around the stem.

• Full Port / Reduced Port Types: Full port construction eliminates flow restriction and erosion at the seat location.

Industries and Applications of slurry knife gate valve:

Working Pressure & Temperature Range:

• Pressure Rating: Up to 150 psi / 10 bar for resilient seated designs higher ratings available with metal seated construction.

• Temperature Range: -20°C to +200°C (-4°F to +392°F), depending on seat material selection.

• Size Range: DN50 to DN1200 (2" to 48").

End Connections Offered:

• Wafer/Lug Style: Fits between pipeline flanges, allowing installation with standard bolt patterns.

• Flanged Ends: ANSI/DIN flange connections for bolted pipeline integration.

• Flangeless Design: Reduces overall weight and installation footprint in tight piping layouts.

Materials Used in Construction:

• Body: Cast iron, ductile iron, carbon steel, stainless steel (SS304/SS316)

• Gate: Stainless steel, hardened stainless steel, or ceramic coated alloy

• Seat: Natural rubber, EPDM, Neoprene, Buna-N, Viton, polyurethane, or metallic seat

• Stem: Stainless steel, machined to endure repeated cycles

Testing & Inspection:

• Hydrostatic Shell Test: Confirms body integrity at rated pressure.

• Seat Leakage Test: Verifies shutoff performance per bidirectional or unidirectional rating.

• Cycle Testing: Confirms gate and seat durability under repeated open close operation with abrasive media simulation.

• Dimensional Inspection: Checks conformance to face to face and flange drilling standards.

• Material Certification: Mill test certificates (MTC) issued per EN 10204 3.1 for material traceability.

Standards and Specifications:

• MSS SP-81 - Knife Gate Valve Design Standard

• API 609 - Butterfly and Knife Gate Valve Category

• ASME B16.5 / B16.34 - Flange and Pressure-Temperature Ratings

• ISO 9001 Manufacturing Practices

Actuation Options:

• Manual Handwheel Operation

• Gear Operated (for larger bore sizes)

• Pneumatic Cylinder Actuation

• Electric Actuator Operation