Zubi RC Round / Square Knife Gate Valve
The Zubi RC Round/Square is a wafer-type knife gate valve designed for challenging discharge, recycling, pulp, and bulk solids applications. Its geometry features a circular inlet and a larger square outlet to minimize material jamming during the passage of solids or fibers.
Construction and Operation
The body is cast, split, two-piece, with internal machining and reinforcement ribs for larger diameters. Replaceable internal guides support the knife movement, while the oversized knife is polished on both sides to reduce friction on guides, seat, and packing.
Applications
Typical installation locations:
- sand traps and rubbish traps in pulpers,
- high consistency cleaners,
- silo outlets with solid materials,
- recycling, pulp, mining, and bulk handling,
- water/wastewater, chemical industry, food, and power plants.
Pressure, Connections, and Sealing
- DN50–DN250: 10 bar
- DN300–DN450: 6 bar
- DN500–DN600: 4 bar
- Higher pressures: upon application review
- Flanges: PN6/10/16/25/40, ANSI 125/150, BST D/E, JIS 5K/10K, AS-2129 D/E
- Sealing: metal/metal, PTFE, or watertight execution
Materials and Seat Selection
Body: GG25, GGG40, A216 WCB, CF8, CF8M, CF3M, 254SMO, 654SMO, AISI310, 904L, Duplex SAF2205, Superduplex SAF2507.
Seats: EPDM, NBR, Silicone, Viton, Graphite, Flucast, or PTFE.
Packing: Synt+PTFE, pure PTFE, graphite, ceramic, or greased cotton. Selection based on temperature, pH, abrasiveness, and leakage requirements.
Actuation
Available with handwheel, lever, gearbox, chain wheel, pneumatic, hydraulic, or electric actuator. Optional: limit switches, proximity sensors, solenoid valves, positioner 4–20 mA, locking devices, cleaning holes, bonnet, and regulation V-ports.
FAQ
When is it chosen over a circular knife gate?
When the line connects a circular inlet to a square discharge or when the material tends to bridge/jam.
Is it a control valve?
Primarily used as on/off isolation or discharge. For throttling, flow rate control, seat wear, and potential use of V-port must be considered.