Knife gate valve - an efficient cutting solution for solid media

In the transportation of solid particles or fibrous media, traditional gate valves or ball valves are often prone to blockage and seal failure. ButKnife Gate ValveWith its unique blade shaped gate structure, it has become a reliable choice for cut-off valves in slurry, sewage, slurry and other working conditions.

1、 Structural characteristics and working principle

The gate of the knife gate valve is shaped like a thin blade and moves perpendicular to the flow direction during the opening and closing process, with a slanted cut at the bottom. This design can easily cut off impurities such as fibers, particles, and mud, avoiding the accumulation of media on the sealing surface.

The valve is mainly composed of a valve body, a gate plate, a sealing ring, a packing box, and a driving device. Most knife gate valves adopt a forced sealing structure, relying on external force to press the gate; A few structures utilize medium pressure to self seal.

When the valve is opened, the gate completely separates from the flow channel, the fluid channel is unobstructed, and the flow resistance is small; When closed, the gate cuts off the medium from top to bottom, seals tightly, and prevents leakage.

2、 Main performance advantages

Strong cutting ability

Knife type gate plates can scrape off sealing surface attachments like blades, especially suitable for media containing particles, slurry, or high viscosity.

Low flow resistance and low energy consumption

When fully open, the flow channel is straight and there is almost no pressure loss, making the system run more efficiently.

• Compact structure and light weight

The commonly used clamp type structure makes valve installation take up less space and weigh about 30% less than traditional gate valves, making it easy to maintain and replace.

• Wear resistant and corrosion-resistant

Stainless steel, ceramics, polyurethane lining and other materials can be selected to adapt to various complex media such as mud, slurry, chemicals, etc.

3、 Driver form and applicable scenarios

Knife gate valves can be configured with different driving modes according to usage requirements:

• Manual type:Simple structure, low cost, suitable for occasions with low switching frequency.

Pneumatic type:Fast response speed, capable of remote automatic control, commonly used in automated production lines such as sewage treatment, chemical industry, papermaking, etc.

• Electric type:It can be linked with the control system and is suitable for working conditions that require opening and closing accuracy.

• Hydraulic type:Used for large caliber, high-pressure systems, with high opening and closing force and smooth operation.

Typical application areas:

Municipal sewage and industrial wastewater treatment system

Paper pulp pipeline and pulp conveying system

Chemical and metallurgical industries including solid medium pipelines

• Ash and slag treatment system for thermal power plants

4、 Selection and maintenance suggestions

1. Choose the valve body and sealing material according to the properties of the medium, and recommend hard alloy or ceramic seals for wear-resistant applications.

2. During installation, keep the valve body concentric with the pipeline to prevent uneven stress on the gate plate.

3. Regularly check the packing seal and guide rail lubrication to prevent long-term wear and tear from causing jamming.

4. For automation systems that frequently open and close, it is recommended to use pneumatic or electric actuators and equip them with limit feedback devices.

V. Conclusion

Knife gate valves have become the main choice for solid medium conveying systems due to their strong cutting ability, lightweight structure, wear and corrosion resistance.

Whether it is the sludge discharge pipeline of sewage treatment plants, or high load conditions such as chemical, mining, and papermaking, as long as there are problems of "blockage, grinding, and corrosion", knife gate valves can reliably and cleanly cut off performance, ensuring long-term stable operation of the system.