Centric butterfly valves, also known as concentric butterfly valves, are a type of quarter-turn valve commonly used in various industries for flow control. The term “centric” refers to the centering of the disc within the valve body. Here are key features and characteristics of centric butterfly valves:
- Concentric Design:
- In centric butterfly valves, the valve disc is centered within the valve body, creating a concentric design. The disc rotates around the centerline of the valve.
- Butterfly Disc:
- The valve disc is mounted on the shaft, and it rotates around the centerline of the valve body. When the valve is open, the disc rotates perpendicular to the flow direction, allowing for unrestricted flow.
- Seating Options:
- Centric butterfly valves can have either soft or metal seats. Soft seats are typically made of materials like rubber, elastomers, or PTFE for applications where tight shut-off is required. Metal seats may be used for higher-temperature and more robust applications.
- Low Torque Requirement:
- The concentric design often results in a lower torque requirement for valve operation, making them easier to actuate and reducing wear on the valve components.
- Bi-Directional Sealing:
- Centric butterfly valves are designed for bi-directional sealing, meaning they can provide a tight seal regardless of the flow direction. This feature adds versatility to their applications.
- Applications:
- These valves are commonly used in various industries, including water treatment, HVAC systems, chemical processing, and general fluid-handling applications where moderate pressure drops are acceptable.
- End Connections:
- Centric butterfly valves can have different end connections, including wafer, lug, or flanged designs. The choice of end connection depends on the specific requirements of the piping system.
- Manual and Automated Operation:
- Centric butterfly valves can be operated manually using a lever or handwheel. They can also be automated using electric or pneumatic actuators for remote control and precise flow regulation.
- Versatility:
- These valves are versatile and find application in various fluid-handling systems, including those involving water, air, gas, and a range of process fluids.
- Cost-Effective:
- Centric butterfly valves are often considered cost-effective solutions for applications where tight shut-off is not critical, and moderate pressure drops are acceptable.
- Ease of Installation and Maintenance:
- Centric butterfly valves are generally easy to install and maintain due to their simple design and fewer components compared to other types of valves.
While centric butterfly valves are suitable for many applications, their use may be limited in scenarios where absolute tight shut-off is required or in applications with high-pressure differentials. Careful consideration of the specific requirements of the system, including pressure, temperature, and fluid characteristics, is essential for proper valve selection and performance. Regular maintenance and adherence to manufacturer recommendations contribute to the efficient and reliable operation of centric butterfly valves.