Wafer-type butterfly valves and flanged butterfly valves are two common types of butterfly valves in industrial pipeline systems, and they have significant differences in structure, installation methods and application scenarios. The following are the specific differences between the two:

1. Structural features

Wafer-type butterfly valve

There are no flanges on both sides of the valve body. Usually, there are only a few guide bolt holes.

It has a simple structure, small volume and light weight, and is composed of a few parts, such as the valve body, valve stem, butterfly plate and valve seat.

Sealing method: Elastic sealing is usually adopted. The sealing ring can be embedded in the valve body or attached to the periphery of the butterfly plate.

Flanged butterfly valve

The valve body is equipped with flanges on both sides and is connected to the pipe flanges through bolts.

The structure is relatively complex, but the sealing performance is more reliable.

Sealing method: Composite valve seats (such as polytetrafluoroethylene and synthetic rubber) are adopted to ensure good sealing.

2. Installation method

Wafer-type butterfly valve

Installation method: Use double-ended bolts to clamp the valve between the two pipe flanges.

Advantages: Easy to install and suitable for occasions with limited space.

Disadvantage: During disassembly, it may affect the other end of the pipe because if one sealing surface has a problem, both sealing surfaces need to be disassembled.

Flanged butterfly valve

Installation method: Connect to the pipe through a flange and fasten with bolts.

Advantages: Reliable sealing, and disassembly will not affect the other end of the pipe.

Disadvantages: The installation is relatively complex and requires more space and bolts.

3. Application Scenarios

Wafer-type butterfly valve

Applicable scenarios: Pipeline systems in industries such as petrochemicals, power, and metallurgy, as well as building water supply and drainage systems.

Features: Suitable for medium and small diameter pipes, easy to install and maintain, and relatively low cost.

Flanged butterfly valve

Applicable scenarios: Equipment in water supply and drainage systems of water plants, power plants, steel mills, etc., where high sealing performance is required.

Features: Suitable for larger-diameter pipes, with more reliable sealing performance, but higher cost.

4. Comparison of advantages and disadvantages

Wafer-type butterfly valve

Advantages: Simple structure, easy installation and low cost.

Disadvantages: The sealing performance may be inferior to that of flanged butterfly valves, and disassembly may affect the other end of the pipeline.

Flanged butterfly valve

Advantages: Reliable sealing performance and suitable for larger-diameter pipes.

Disadvantages: Complex structure, relatively troublesome installation, and high cost.

5. Sealing performance

Wafer-type butterfly valve

The sealing performance depends on the elastic sealing ring, which is suitable for general media and pressure.

Flanged butterfly valve

The adoption of composite valve seats ensures more reliable sealing performance and is suitable for high-pressure and corrosive media.

Summary

The main differences between wafer-type butterfly valves and flanged butterfly valves lie in their structures, installation methods and application scenarios. The wafer-type butterfly valve has a simple structure and is easy to install, making it suitable for medium and small diameter pipelines. Flanged butterfly valves have more reliable sealing performance and are suitable for larger diameters and applications with high sealing requirements. When making a choice, a comprehensive consideration should be given to factors such as specific working conditions, medium and pressure.