Main Parameters
• Pressure: Primarily PN10 and PN16
• Temperature: Generally ≤ 120℃
• Diameter: DN50～DN1000 (Very common)
• Seal: Soft seal and hard metal seal
• Drive method: Handwheel, bevel gear, pneumatic, electric
Applicable Media
• Sewage, sludge, mud, slurry
• Pulp, fiber, mineral slurry
• Dust, fly ash, powder
• Wastewater treatment plants, paper mills, mines, metallurgy, ash and slag pipelines
Ceramic knife gate valves (also known as ceramic knife-type gate valves) are special valves that combine a knife gate valve with a high-performance ceramic seal. The core seal and flow components are made of toughened alumina/silicon carbide ceramic, while the valve body is typically made of carbon steel (WCB) or stainless steel (304/316L).
Structure and Principle
• The opening and closing element is a knife-edged gate, moving perpendicular to the media flow direction, cutting media containing particles and fibers through shearing.
• The gate rises and falls within a side guide groove, and the bottom lug tightly presses against the valve seat, eliminating cavities, slag accumulation, and jamming.
• The valve seat commonly uses a protective lip ceramic ring + O-ring to achieve a bidirectional hard seal, with a leakage level reaching ANSI Class VI.
Structural Features
• The gate is longer than the valve body, allowing it to completely penetrate the valve body during opening and closing.
• It has a guide bracket at the top and generally an outlet cover/discharge port at the bottom.
• The gate operates more stably, without deviation or bending.
• Mostly wafer or flange type, providing greater overall rigidity.
• Driven manually, pneumatically, or electrically.
Core Structure
• Valve Body: Ductile iron/WCB, fully lined with polyurethane (PU)
• Gate: Stainless steel (304/316/2205) + polyurethane coating
• Sealing: Polyurethane seat (soft seal)
• Connection: Wafer type / Flange type
• Drive: Manual, pneumatic, electric, bevel gear
Structural Features
• Ultra-thin valve body, simple structure
• Gate moves vertically like a blade, providing a shearing action
• Mostly wafer type, flange type also available
• Sealing relies on the fit between the gate and the valve seat, with built-in scraping function
Core Advantages
• Anti-clogging and anti-jamming: capable of cutting fibers, slurry, and particles
• Small size, light weight, and small installation space
• Straight flow path with no dead angles, minimal flow resistance
• Inexpensive and easy to maintain
• Shearing action during opening and closing, suitable for media containing impurities
