- Design: Knife gate valves have a unique design that includes a sharp-edged gate that moves vertically to cut through and clear any material in the pipeline. When the valve is open, it provides an unobstructed flow path, and when closed, it creates a tight seal.
- Materials:
- Body Materials: Commonly made from cast iron, carbon steel, stainless steel, or alloy steels.
- Gate Materials: Stainless steel, alloy steels, or other corrosion-resistant materials.
- Seat Materials: Elastomers like EPDM or NBR, or metal seats for high-temperature and high-pressure applications.
- Pressure Rating: Knife gate valves are available in various pressure ratings, often determined by standards such as ANSI Class 150, 300, 600, etc. This ensures that the valve can handle the pressures of different applications.
- Size Range: These valves come in a wide range of sizes to accommodate different pipeline diameters, from small to large.
- End Connections: Available with various end connections including flanged, wafer, or lug-type connections, depending on the installation and piping requirements.
Knife Gate Valve
Knife Gate Valve
A knife gate valve is a type of valve used primarily for on/off control of flow in applications where the media is thick, viscous, or contains solids. It is designed to handle slurries, sludges, and other challenging materials that might be difficult for other valve types to manage.
General Description
- Function: Knife gate valves are used to isolate or control flow in pipelines, especially where the fluid contains solids or where a tight shut-off is required. The valve is called a “knife gate” because the gate or blade is sharp-edged and designed to cut through materials like slurries and fibrous or sticky substances.
- Construction: The main components of a knife gate valve include:
- Gate (Blade): A sharp-edged, flat blade that moves up and down to open or close the valve. The blade’s design allows it to slice through materials and create a tight seal when closed.
- Body: The main structure of the valve that houses the gate and other internal components. It is often made from durable materials such as cast iron, carbon steel, or stainless steel.
- Stem: Connects the gate to the actuator or manual handle and provides the means for vertical movement of the gate.
- Seats: Surround the gate to provide a sealing surface when the valve is closed. Seats can be made from materials like elastomers or metals, depending on the application.
- Mining and Minerals Processing, Pulp and Paper, Water and Wastewater Treatment, Chemical Processing.
- Knife gate valves can be operated manually with a handwheel or lever, or automatically with electric or pneumatic actuators. The quarter-turn or linear movement allows for easy and precise control of the valve.