Knife gate valve is also known as knife gate valve, slurry valve and mud valve.
Its opening and closing part is a gate, and the movement direction of the gate is perpendicular to the direction of the fluid. It is cut off by a blade-shaped gate that can cut fiber materials. Medium, the gate has two sealing surfaces. The two sealing surfaces of the most commonly used mode gate valve form a wedge shape. The wedge angle varies with the valve parameters, usually 5°. The gate of the wedge type knife gate valve can be made into a The whole is called a rigid gate; it can also be made into a gate that can produce a small amount of deformation to improve its manufactur ability and make up for the deviation of the angle of the sealing surface during processing. This gate is called an elastic gate. There is actually no chamber in the valve body, the gate rises and falls in the side guide groove, and is pressed against the valve seat by the lugs at the bottom. If a higher medium sealing performance is required, an O-ring sealing valve seat can be used to achieve Two-way sealing.
The knife gate valve has small installation space, low working pressure, not easy to accumulate debris, and low price.
When the knife gate valve is closed, the sealing surface can be sealed only by the medium pressure, that is, relying on the medium pressure to press the sealing surface of the gate to the valve seat on the other side to ensure the sealing of the sealing surface, which is self-sealing. Most gate valves are With forced sealing, that is, when the valve is closed, the gate must be forced against the valve seat by external force to ensure the tightness of the sealing surface. This type of valve should generally be installed vertically in the pipeline.
What is the pressure for knife gate valve?
Knife gate valve cannot withstand high pressure due to its structural characteristics. The actual working pressure depends on the diameter of the pipeline:
DN50-DN150, working pressure 1.0MPa;
DN200, working pressure 0.8MPa;
DN250-DN300, working pressure 0.6MPa;
DN350-DN400, working pressure 0.5 MPa;
DN450-DN600, working pressure 0.3MPa.
The test pressure is 1.5 times the working pressure for the body, and the sealing test pressure is 1.1 times of working pressure.
What is the application for knife gate valve?
Knife gate valves are used in the following areas: