Single-eccentric butterfly valves are industrial components engineered to efficiently control the flow of working media within a pipeline. While these valves are adept at fully opening or closing a passage, they are also suitable for flow-control purposes. However, it’s important to note that achieving 100% tightness over the long term, especially in applications where precise control is essential, may present challenges. Here’s a detailed description of their design and considerations:

1. Flow Control and Shut-Off Capability:

• Versatile Functionality: Single-eccentric butterfly valves are versatile, offering the capability to fully open or close a passage within a pipeline. This makes them suitable for applications where on/off control is required.

2. Eccentric Design:

• Single Eccentricity: The valve features a single eccentric design, with the shaft offset from the center of the butterfly disc. This design allows for precise control of the opening and closing of the valve.

3. Flow-Control Applications:

• Variable Opening Positions: While primarily used for on/off applications, these valves can also be utilized for flow-control purposes by adjusting the opening position. This is beneficial when moderate control of fluid flow is sufficient for the application.

4. Tightness Considerations:

• Challenges in Long-Term Tightness: Achieving and maintaining 100% tightness over the long term, especially in applications demanding stringent control, can pose challenges. Factors such as wear, temperature variations, and fluid characteristics may impact the long-term sealing capability.

5. Materials and Construction:

• Material Selection: The construction of single-eccentric butterfly valves involves materials selected for compatibility with the working medium and the environmental conditions. This includes considerations for corrosion resistance and durability.

6. Leakage Mitigation Measures:

• High-Quality Seals: While 100% tightness may not be guaranteed over the long term, these valves incorporate high-quality seals to minimize the risk of leakage. Proper maintenance and periodic inspections are essential to ensure optimal performance.

7. Actuation Options:

• Manual or Automated: Single-eccentric butterfly valves can be operated manually using a lever or handle, or they can be automated with electric, pneumatic, or hydraulic actuators for remote and precise control.

8. Cost-Effective Solution:

• Economical Design: These valves are often considered a cost-effective solution for applications where precise control is not the primary requirement. Their straightforward design and ease of operation make them a popular choice in various industries.

9. Applications:

• Water Treatment: Single-eccentric butterfly valves are commonly used in water treatment plants for flow control and shut-off applications.
• General Industrial Processes: They find applications in a wide range of industrial processes where moderate control of fluid flow is sufficient.