I. Product Introduction
The Pneumatic Knife Gate Valve is a heavy-duty on-off and flow control device that combines a sharp-edged gate plate with a high-thrust pneumatic actuator, specifically engineered for handling viscous, particulate-laden, and fibrous media. It is widely used in industries such as mining, wastewater treatment, pulp and paper, food processing, chemical engineering, and power generation, where conventional valves are prone to clogging or wear.
Featuring a unique “knife-edge” gate plate design, the valve cuts through sticky solids, slurries, and sludge during opening and closing, ensuring unobstructed flow and preventing medium accumulation within the valve body. The pneumatic actuator provides fast, stable linear motion to drive the gate plate, enabling automated and remote operation that improves process efficiency and reduces manual labor. With its robust structure and wear-resistant components, this valve maintains reliable performance in harsh working conditions, including high abrasion, high viscosity, and high solids content scenarios, making it an essential component for heavy-duty industrial pipeline systems.
II. Product Features
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Efficient Medium Cutting PerformanceThe gate plate is precision-machined with a sharp, hardened edge that can slice through fibrous materials, slurries, and media with high solid content, effectively preventing clogging and ensuring smooth on-off operation. The full-bore straight-through channel design minimizes flow resistance and pressure loss, avoiding medium deposition and reducing maintenance frequency.
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Powerful and Reliable Pneumatic ActuationEquipped with a high-thrust pneumatic actuator (double-acting or single-acting spring return type), the valve achieves fast opening and closing with a response time of 3–8 seconds (depending on valve size). The single-acting actuator offers fail-safe protection: when air supply is interrupted, the spring force drives the gate plate to the preset open or closed position, preventing pipeline blockage or system overpressure and enhancing operational safety.
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Superior Sealing and Wear ResistanceAdopts two sealing options for diverse working conditions: elastic seat sealing (PTFE, NBR, EPDM) achieves tight sealing with zero leakage for general media; metal-to-metal sealing (stainless steel gate plate and seat) provides excellent wear and high-temperature resistance for abrasive and high-temperature media. The gate plate surface is treated with hardening or ceramic coating to enhance wear resistance and extend service life.
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Robust and Corrosion-Resistant StructureThe valve body and gate plate are made of high-quality materials, including carbon steel (WCB), stainless steel (304/316/316L), and duplex stainless steel, selectable according to medium corrosivity. The inner surface of the valve body is polished or coated with anti-corrosion materials to resist erosion by acidic, alkaline, or abrasive media. The overall structure is lightweight yet sturdy, suitable for installation in narrow spaces and heavy-duty working environments.
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Easy Installation and MaintenanceFeatures flexible connection modes, including wafer, lug, and flange types, compatible with international standards (GB, DIN, ANSI, JIS) for quick integration into various pipeline systems. The split-type actuator and valve body connection design allows for easy disassembly and maintenance without removing the entire valve from the pipeline. The actuator is equipped with NAMUR standard interfaces, supporting seamless connection with solenoid valves, limit switches, and positioners for automated control and status monitoring. An optional manual handwheel is available for emergency operation when the pneumatic system fails.
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Wide Application AdaptabilitySuitable for media such as slurry, sludge, pulp, coal ash, ore pulp, wastewater, and viscous liquids, with nominal diameters ranging from DN50 to DN2000 and nominal pressures from PN0.6 to PN16. It operates stably in a temperature range of -20°C to 300°C, adapting to various harsh industrial process requirements and complying with ISO, API, and other international standards.
III. Technical Data
| Technical Parameter | Specification |
|---|---|
| Nominal Diameter (DN) | DN50 – DN2000 (customizable for special requirements) |
| Nominal Pressure (PN) | PN0.6 – PN16; Class 150 |
| Working Temperature Range | -20°C – 300°C
(Elastic seat: -20°C–180°C; Metal seat: -20°C–300°C) |
| Applicable Medium | Slurry, sludge, pulp, coal ash, ore pulp, wastewater, viscous liquids, fibrous materials, etc. |
| Valve Body Material | Carbon steel (WCB), Stainless steel (304/316/316L), Duplex stainless steel |
| Gate Plate Material | Stainless steel (304/316) with hardening treatment, Ceramic-coated stainless steel, Hastelloy (for strong corrosion) |
| Seal Material | Elastic seat: PTFE, NBR, EPDM, FKM
Metal seat: Stainless steel (304/316), Hardened alloy steel |
| Actuator Type | Pneumatic double-acting actuator, Pneumatic single-acting actuator (spring return) |
| Actuator Air Supply Pressure | 0.4 – 0.8 MPa |
| Response Time | 3 – 8 seconds (varies by valve size and actuator model) |
| Leakage Rate | Elastic seat: ANSI Class VI (zero leakage)
Metal seat: ANSI Class IV |
| Connection Type | Wafer type, Lug type, Flange type (GB/T, DIN, ANSI, JIS), Clamp type (sanitary application) |
| Control Signal (Optional) | 4–20 mA DC (with positioner for proportional control) |
| Actuator Protection Grade | IP65 (standard), IP67 (optional for outdoor/harsh environment) |
| Service Life | ≥ 50,000 cycles (normal working conditions) |
| Operation Mode | Automatic (pneumatic control), Manual (optional handwheel for emergency use) |
| Standards Compliance | Design: ISO 5752, API 609; Testing: API 598 |
Ⅳ．The main shape and connection size
