Absperrschieber

Product Overview

The Electric Knife Gate Valve is a knife‑edge gate valve driven by an electric actuator, designed only for ON‑OFF (open/close) service – not for flow regulation. It is widely used in automated piping systems in papermaking, wastewater treatment, mining, chemical, and power generation industries for remote shut‑off of media. The sharp knife‑edge gate cuts through hanging fibers, paper, plastic strips, and other materials during closure, preventing clogging.

The body flow path has no recesses, providing self‑cleaning action. A bidirectional sealing option is available for applications requiring pressure containment from either direction. The valve has flanged connections, with nominal diameters from DN50 to DN1200, pressure ratings PN10/PN16 (Class 150), and body materials including cast iron, carbon steel, and stainless steel. The electric actuator is equipped with a handwheel, limit switches, and optional explosion‑proof features.

Produktstruktur

The Electric Knife Gate Valve mainly consists of the electric actuator (ON‑OFF type) und knife gate valve body assembly.

Electric Actuator (ON‑OFF Type):

1. Motor: Reversible motor providing driving force.

2. Gearbox: Gear or worm‑gear reducer delivering high torque.

3. Travel Limit Switches: Adjustable switches to control fully open and fully closed positions.

4. Torque Limit Switch: Overload protection to prevent valve damage if the gate jams.

5. Handwheel Mechanism: Manual override for on‑site commissioning and emergency operation.

6. Terminal Box: For connection of power, ON‑OFF control signal, and feedback signal.

7. Optional Accessories: Explosion‑proof actuator, dry contact limit switches, bus communication (Modbus, Profibus), etc.

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Knife Gate Valve Body Assembly:

1. Gehäuse: Cast or fabricated body in gray cast iron, ductile iron, carbon steel (WCB), stainless steel (CF8/CF8M), etc. Flanged ends conforming to GB/T 9113, ANSI B16.5, EN 1092‑1, etc. Full‑bore flow path with no pockets to prevent material buildup.

2. Schieber: Stainless steel (304, 316, 310S) knife‑edge gate with a sharp edge to cut through fibers and particles. The gate surface can be hardfaced with Stellite or chrome‑plated for improved wear resistance.

3. Dichtungen: Available in unidirectional or bidirectional sealing. Seat materials include rubber (EPDM, NBR, FKM), PTFE, metal (Stellite hardfaced), or ceramic.

4. Spindel: Stainless steel trapezoidal‑thread stem, connected to the gate at the bottom and to the electric actuator output shaft at the top.

5. Stopfbuchse: Enthält PTFE- oder flexible Graphitpackung, die durch eine Stopfbuchsenbrille komprimiert wird, um äußere Leckagen zu verhindern.

6. Joch: Connects the body to the electric actuator.

Compact construction; electric control enables remote ON‑OFF operation.

Funktion

1. Remote Electric ON‑OFF Control: Receives an ON‑OFF signal (AC 220V, DC 24V, etc.) from DCS or PLC to automatically open or close the valve, allowing unattended operation.

2. Schneidfunktion mit scharfer Kante: The sharp edge of the gate cuts through hanging fibers, paper, plastic strips, rags, and other materials during closure, preventing clogging.

3. Selbstreinigender Strömungsweg: Der Strömungsweg im Gehäuse weist keine Hinterschneidungen auf. Bei voller Öffnung kann das Medium das Innere spülen und so die Ansammlung von Feststoffen verhindern.

4. Bidirektionale Abdichtung (optional): A bidirectional floating seat or double‑sided sealing design allows the valve to withstand media pressure from either direction, accommodating flow reversal or bidirectional pressure requirements.

5. Vollerdurchgang mit geringem Strömungswiderstand: Bei voller Öffnung befindet sich der Schieber vollständig außerhalb des Strömungswegs, was einen minimalen Druckverlust gewährleistet.

6. Overload Protection: The electric actuator is equipped with a torque limit switch that cuts motor power if the gate jams, protecting both valve and actuator.

7. Manuelle Notbetätigung: The handwheel on the actuator allows manual operation during power failure or actuator fault.

8. Valve Position Feedback: Provides dry contact limit switch signals (fully open / fully closed) for monitoring by a host system.

Arbeitsbedingungen

1. Anwendbare Medien: Pulp, sewage, sludge, mineral slurry, coal slurry, powders, fiber suspensions, particle‑laden liquids, corrosive liquids, etc.

2. Temperaturbereich: –20 °C bis +200 °C (PTFE-Dichtungen); –20 °C bis +80 °C (Gummidichtungen); –29 °C bis +550 °C (Metalldichtungen).

3. Druckstufe: PN10, PN16 (Class 150); höhere Druckstufen auf Anfrage.

4. Nenndurchmesser: DN50 – DN1200 (2″ – 48″); larger sizes available on request.

5. Power Supply: AC 220V, AC 380V (standard); DC 24V optional.

6. Control Signal: ON‑OFF (AC 220V or DC 24V).

7. Feedback Signal: Limit switch contact signals (open / closed).

8. Typische Anwendungen:

   1. Automatic shut‑off of pulp lines in paper mills

   2. Automatic sludge and sewage discharge in wastewater treatment plants

   3. Automatic control of mine tailings transport

   4. Ash and slag discharge in coal‑fired power plants

   5. Automatic batching of chemical fiber and polymer slurries

   6. Fruit pulp and sauce filling lines in the food industry

   7. Automatic dust discharge in steel mills

Zusammenfassung

The Electric Knife Gate Valve (ON‑OFF type), with its advantages of remote electric ON‑OFF control, knife‑edge cutting function, self‑cleaning flow path, and optional bidirectional sealing, is an ideal shut‑off valve for automated piping systems handling media containing solid particles, fibers, or slurries. This valve is designed for fully open or fully closed operation only – not for flow regulation.

Compared with manual knife gate valves, the electric version enables remote control and centralized management, reducing manual intervention. Compared with ordinary electric gate valves, the knife‑edge gate effectively cuts through fibers and particles, preventing clogging. With flanged connections, a full‑bore flow path, and optional explosion‑proof actuators, it is suitable for harsh environments and hazardous areas. For pipeline systems that require automatic ON‑OFF control and handle media containing solids, fibers, or slurries, the Electric Knife Gate Valve is an efficient and reliable solution.