Manual Knife Gate Valve is a valve that controls the flow of fluids through manual operation, primarily used for full-open and full-close operations, and is not adjustable or throttling. Its moving part is the gate plate, which moves perpendicular to the fluid direction.

Structural Features

The manual knife gate valve has a relatively simple and compact structure, primarily composed of the valve body, gate plate (shutter plate), valve rod, and seals. The gate plate usually features two sealing surfaces, commonly in a wedge shape, with the angle varying according to the valve specifications, typically 50 degrees. Depending on the type of sealing surface, the gate plate of the manual knife gate valve can be categorized into rigid and elastic types.

Working Principle

The working principle of the manual slide gate valve is based on the vertical movement of the gate plate to control the flow and cutoff of the medium. When it's necessary to close the valve, the manual operation of the drive mechanism (such as a handwheel) moves the valve rod downward, causing the gate plate to slide down the valve body's guide rail until the sealing surface of the gate plate is tightly seated against the valve seat, thereby cutting off the flow of the medium. Conversely, when it's required to open the valve, the manual operation of the drive mechanism moves the valve rod upward, lifting the gate plate away from the valve seat, allowing the medium to pass through the valve.

Performance Features

Sealed Reliably: The sealing surfaces of manual knife gate valves are typically made of metal or elastic materials, offering excellent sealing performance. In the closed position, the gate plate forms a tight seal against the valve seat, preventing fluid leakage.

‌Operation Simplified: Manual operation makes the valve's on/off process more convenient and quick, without the need for additional power sources._

High wear resistance: Gate plates are typically made of wear-resistant materials, enabling long-term operation in mediums containing solid particles.

Cutting Function: The gate plate features a blade-like design, capable of cutting through fibers, pulp, and other debris in the medium, preventing valve blockages and ensuring the smooth flow of the pipeline.

Application Scenario

Manual knife gate valves are suitable for a variety of media, including pulp, sewage, coal slurry, and ash-water mixtures. The operating temperature range varies depending on the material of the valve and the sealing material. Under general operating conditions, manual knife gate valves using common sealing materials such as rubber and PTFE have an applicable temperature range of -20℃ to 200℃; under special conditions, such as with special alloy materials and hard alloy seals, the applicable temperature range can extend up to 1100℃.

Installation and Maintenance

Manual submersible knife gate valves should generally be installed horizontally in pipelines to ensure proper operation. Attention should be given to the installation direction of the valve and the sealing of the flange connection during the installation process.