Knife gate valves entered my country in the 1980s. In less than two decades, their use has expanded from ordinary fields to a wider range of industries, from coal preparation, gangue discharge, and slag discharge in mines and power plants to Urban sewage treatment has evolved from general industrial pipelines to specialized pipeline systems for food, sanitation, and medicine.

 

Overview

 

Knife gate valve, also known as knife gate valve, knife gate valve, slurry valve, mud valve, its opening and closing part is a gate, the direction of movement of the gate is perpendicular to the direction of the fluid, and 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 model gate valve form a wedge. The wedge angle varies with the valve parameters, usually 50. The gate of the wedge knife gate valve can be made into a whole , It is called a rigid gate; it can also be made into a gate that can produce slight deformation to improve its manufacturability and compensate for the deviation of the angle of the sealing surface during the processing. This kind of gate is called an elastic gate. There is no cavity in the valve body. The gate is raised and lowered in the side guide groove and pressed against the valve seat by the lugs at the bottom. If a higher medium tightness is required, an O-shaped sealing valve seat can be used. Two-way sealing. Knife gate valve has a small installation space, low working pressure, is not easy to accumulate debris, and the price is low.

 

When the knife gate valve is closed, the sealing surface can only rely on the medium pressure to seal, that is, rely 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 Forced sealing is used, that is, when the valve is closed, the gate must be forced to 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.

 

Knife gate valve drive mode: manual, sprocket, electric, pneumatic, hydraulic, bevel gear, electric control hydraulic and pneumatic hydraulic drive. Knife gate valve shape: two types: bright rod and concealed rod. Knife gate valve material: cast iron, cast steel, carbon steel, stainless steel, fluorine lining, etc. Knife gate valve seal: hard seal, soft seal, single-sided seal, double-sided seal and other materials.

 

The ultra-thin knife gate valve completely solves the large flow resistance of ordinary gate valves, flat gate valves, ball valves, globe valves, regulating valves, butterfly valves and other valves with its advantages of small size, small flow resistance, light weight, easy installation, and easy disassembly. , Heavy weight, difficult installation, large area and other difficult problems. After the emergence of knife gate valves, a large number of general shut-off valves and regulating valves have been replaced. To date, the world's largest consumption of knife gate valves is the United States and Japan.

 

The scope of application of the knife gate valve is:

 

1. Mining, coal washing, iron and steel industry-used in coal washing pipelines, filter slurry pipelines, etc., ash discharge pipelines;

 

2. Purification device-used for wastewater, mud, dirt and clarified water with suspended solids;

 

3. Paper industry-used for any consistency of pulp, material and water mixture;

 

4. Deashing of power station-used for ash slurry.