NWV flanged knife gate valves are specifically designed for fluids containing solid particles or fibrous materials, constructed from high-strength ductile iron (GGG50) or stainless steel (304/316).
Port Size:: DN50-DN1200
Power:: Pneumatic
Media:: Sewage,slurry and else
Material:: Stainless Steel
Specification
NWV Flanged Knife Gate Valve: Industrial Solution for Particulate Media Control
I. Product Overview
NWV flanged knife gate valves are specifically designed for fluids containing solid particles or fibrous materials, constructed from high-strength ductile iron (GGG50) or stainless steel (304/316). The vertical-lifting knife gate enables precise flow cutoff, covering DN50-DN600 (2″-24″) with PN10-PN16 (1.0-1.6MPa) pressure ratings. Ideal for sewage, papermaking, and food slurry applications, the blade-shaped gate cuts through viscous media while elastic sealing ensures zero leakage—perfect for industrial solid-liquid mixed fluid control.
II. Core Technical Parameters
Specifications & Pressure Classes
Nominal Diameter: DN50-DN600 (2″-24″), customizable for extra-large sizes
Pressure Rating: PN10/PN16 (1.0MPa/1.6MPa) for medium-low pressure systems
Temperature Range: -20℃~120℃ (standard), -40℃~200℃ (high-temperature customization)
Materials & Sealing System
Body/Gate: Ductile iron GGG50 (tensile strength ≥500MPa), 304/316 stainless steel
Sealing Components: NBR or VITON, leakage rate ≤0.1% (API 598)
Stem: 2Cr13 stainless steel, chrome-plated (HRC35+ hardness) for corrosion resistance
Connection: Flanged (ASME B16.5, GB/T 9113), RF face
Actuation & Operation
Manual Drive: Aluminum handwheel, DN100 operating torque ≤120N·m
Pneumatic/Electric Actuation: Optional, response time ≤1 second
Protection Grade: IP65 (body), Ex d IIB T4 (explosion-proof for electric models)
Product Overview
III. Structural Design & Technical Features
**Knife Gate Flow Optimization
Blade-shaped gate design cuts through fibrous media (e.g., paper pulp, sewage fabrics) to prevent tangling.
Straight-through flow path reduces flow resistance by 25% compared to conventional gate valves, suitable for high-viscosity fluids.
**Elastic Sealing Reliability
Lip-shaped elastic seat design automatically compensates sealing specific pressure (≥8MPa) via medium pressure.
Double-sealing surface grinding precision ≤0.03mm flatness, verified by red lead powder testing.
**Anti-Jamming Details
Gate guide groove tolerance ≤0.1mm ensures precise lifting, avoiding particle jamming.
Inclined body bottom design prevents medium sedimentation, improving self-cleaning by 30%.
IV. Manufacturing Processes & Quality Control
**Precision Casting
Ductile iron castings use lost foam process with graphite spheroidization grade ≥2, eliminating shrinkage defects.
Stainless steel parts undergo 1050℃ solution treatment, grain size ≥Grade 5 for excellent intergranular corrosion resistance.
**High-Precision Machining
Gate blade processed by 5-axis CNC grinder, edge roughness Ra≤1.6μm.
Stem thread precision reaches 6g grade, fit clearance ≤0.05mm.
**3D Quality Inspection
Hydrostatic test: 1.5x working pressure for shell (30min hold), 1.1x for sealing (zero leakage).
Spectral analysis: Element deviation ≤0.05% per heat to ensure material consistency.
NDT: 100% ultrasonic testing (UT), compliant with GB/T 2970 Grade III.
