Manual knife gate valve, also known as a manual knife-type gate valve, is a valve that controls the flow of fluids through manual operation. Its structure is relatively simple and compact, mainly composed of the valve body, valve plate (gate plate), valve stem, and sealing parts. The movement direction of the valve plate is perpendicular to the fluid direction, usually featuring two sealing surfaces. The common pattern is wedge-shaped, with the wedge angle varying with the valve parameters, typically 50 degrees.

Operating Principle

The working principle of manual knife gate valves 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, manual operation of the drive mechanism (such as a handwheel) moves the valve rod downward, causing the gate plate to slide down the guide rail of the valve body until the sealing surface of the gate plate is tightly fitted against the valve seat, thereby cutting off the flow of the medium; when it's necessary to open the valve, 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

Seal Reliability: The sealing surfaces of manual knife gate valves are typically made of metal or elastic materials, offering excellent sealing properties. In the closed position, the gate plate and valve seat form a tight seal to prevent fluid leakage.

Operation Simple: The valve can be opened and closed by manually operating the driving device without requiring an additional power source.

High abrasion resistance: Gate plates are typically made of wear-resistant materials, enabling them to work for extended periods in media containing solid particles.

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

Wide Application Range: Suitable for various media, including pulp, wastewater, coal slurry, slag water mixtures, etc., with a broad temperature range from -20℃ to as high as 1100℃.

Application Scenarios

Manual knife gate valves are widely used in various fields:

Papermaking Industry: Used for processing pulp, fibers, etc., capable of cutting debris within the medium to ensure the unobstructed flow of pipelines.

‌Wastewater Treatment: Used in urban wastewater treatment plants and industrial wastewater treatment systems, for the removal of suspended solids, fibers, and other impurities from wastewater.‌

‌Mining Industry: Used for coal selection and slag removal in mines, capable of processing mediums containing coal gangue, ore particles, and other impurities.‌

‌Food Industry: Control the conveyance of fluid materials in food processing, such as in the production of milk, juice, beer, etc., where these materials can be cut off and directed through pipes.