Knife Gate Valve

Knife gate valve, also known as knife-type gate valve, knife door, slurry valve and mud valve, adopts a knife-type gate plate with excellent shearing performance. It is suitable for hard-to-control fluids such as slurry, powder granular materials and fibers, and is widely used in industries like papermaking, petrochemical, mining, drainage and food processing.It offers a variety of valve seats for selection, and can be equipped with electric or pneumatic actuators according to on-site control requirements to realize automatic operation of the knife gate valve.

The opening and closing part of a knife gate valve is the gate plate, whose movement direction is perpendicular to the fluid direction. Knife gate valves can only be fully opened and fully closed, and cannot be used for regulation and throttling.The gate plate has two sealing surfaces. The two sealing surfaces of commonly used pattern gate valves form a wedge shape, and the wedge angle varies with valve parameters, usually 50 degrees. The gate plate of a wedge-type knife gate valve can be made as a whole (called a rigid gate plate) or a gate plate that can produce slight deformation (called an elastic gate plate) to improve processability and make up for the deviation of the sealing surface angle during processing.When a knife gate valve is closed, the sealing surface can be sealed by medium pressure (relying on medium pressure to press the gate plate’s sealing surface against the opposite valve seat) — this is called self-sealing. Most knife gate valves adopt forced sealing: when the valve is closed, external force is used to press the gate plate against the valve seat to ensure sealing performance.

Working Principle and Applications of Knife Gate Valve:

• Knife gate valves are mainly composed of a knife blade (gate plate) and a supporting structure. The working principle of this equipment is to control the flow direction of fluids by changing the position of the knife blade.
• When the knife blade is fully open, fluids can flow freely; when it is fully closed, fluids cannot flow. Between these two states, partial opening or closing of the knife blade can make the fluid flow reach a predetermined value.This flexible control method enables knife gate valves to find suitable positions in many industrial applications.
• The characteristics of knife gate valves include simple operation, easy installation, strong pressure resistance and so on. However, knife gate valves also have certain shortcomings. For example, after long-term use, the knife blade may suffer from wear, leakage and other issues. Therefore, when choosing to use knife gate valves, it is necessary to consider according to actual application conditions and requirements.
• For example, in the food processing industry, knife gate valves can be used to control the flow of water to ensure accurate water volume in each processing process. In the oil and gas industry, knife gate valves can be used to control the flow of oil and gas to ensure the safe transportation of oil and gas.Generally speaking, knife gate valves are practical and economical fluid control equipment, which are favored by a large number of users.

Installation and Use of Manual Knife Gate Valve:

• Before installing the manual knife gate valve, check the valve cavity and sealing surface — no dirt or sand is allowed to adhere;
• Tighten the bolts at each connection part of the manual knife gate valve evenly;
• Check the packing part of the manual knife gate valve and press it tightly to ensure both sealing performance and flexible gate plate opening;
• Before installation, verify the manual knife gate valves model, connection size and fluid direction to match the valves requirements;
• Reserve necessary space for the manual knife gate valves driving device during installation;
• Wire the driving device according to the circuit diagram;
• Maintain knife gate valves (including manual ones) regularly; do not collide or squeeze them randomly to avoid sealing damage.

Mounting Dimension