Characteristics and Classification of Gate Valves

A gate valve is a type of valve in which the gate moves vertically along the centerline of the passage. It is primarily used for cutting off in pipelines.

Gate valves are widely used valves, commonly selected for cut-off devices with an nominal diameter (DN) of 50mm or more. Sometimes, even those with very small diameters are used.

Cut-off devices are also chosen with gate valves.

Gate valves have the following features:

Low fluid resistance.

The required external force for opening and closing is minimal.

Flow of the medium is unrestricted.

④ When fully open, the sealing surface is subject to erosion by the working medium, which is less than that of a full-bore valve.

⑤The body shape is relatively simple and has good casting processability.

Gate valves also have their limitations:

The dimensions and opening height are both large. The required installation space is substantial.

During the opening and closing process, there is relative friction between the sealing surfaces, which is prone to cause abrasion.

Check valves typically have two sealing surfaces, which add some difficulties to the processing, grinding, and maintenance.

Gate valves can be categorized in various ways based on different standards, mainly including classifications by gate plate structure, material, and operation method.

By gate structure classification:

Wedge Gate Valve: The gate is wedge-shaped, controlling the medium through the配合 between the wedge structure and the valve body, offering good sealing performance.

Fluid Control Solutions for Medium and High Pressure Applications

2. Parallel Gate Valve: The gate plate is parallel to the vertical centerline, with sealing surfaces also parallel, suitable for low-pressure medium and small bore sizes.

3. Rotating Gate Valve: The gate is circular or semi-circular, achieving medium shut-off and adjustment through rotation.

4. Elastic Seat Sluice Valve: Coated with an elastic material on the gate plate, enhancing sealing and controlling the flow of the medium.

5. Sludge Gate Valve: Equipped with an outlet on the gate plate, designed for cleaning impurities and pollutants from pipelines.

‌By Material Category‌

Metallic Valve Materials: Carbon steel, alloy steel, stainless steel, cast iron, titanium alloy, etc.

‌2. Metal Valve Body Lining Valves: Such as lined with rubber, fluorine, lead, etc.

3. Non-metallic Valve Materials: Such as ceramics, glass, and plastics.

‌By Operation Method Category‌

Manual Gate Valve: Operation is achieved by rotating the handwheel to open and close the valve stem.

2. Electric Gate Valve: Powered by electricity, suitable for remote or automated control.

Additionally, gate valves can be further subdivided based on their structure and application, such as flat gate valves, knife gate valves, and so on. They can also be categorized by connection size into mechanical standard valves, national standard valves, and American standard valves, etc.