Butterfly valves are some of the most common valves found in industrial fluid handling systems. They are popular due to their simple design, lightweight construction, fast operation, and low cost compared to other valve types. While most butterfly valves have a concentric disc design, the eccentric butterfly valve offers some notable performance advantages. In this blog, we’ll take a closer look at what makes eccentric butterfly valves different and why they may be the best choice for certain applications.
What is an Eccentric Butterfly Valve?
Unlike a concentric butterfly valve which has a symmetrical disc aligned with the centerline of the valve body, an eccentric butterfly valve has an asymmetrical disc offset from the centerline. As the disc rotates to open and close the valve, this offset translates to a cam action that pushes the disc against the valve seat. This provides a tight, bubble-tight shutoff without requiring high torque and wear on the seals.
The offset disc design causes the disc to seal consistently in the lower quadrant of the pipe first before closing fully. This allows for improved flow control and lower pressure drops compared to concentric designs. The tight shutoff enabled by the eccentric design also makes them well-suited to handling corrosive, toxic, or dangerous fluids and gases.
Benefits of Eccentric Butterfly Valves
There are several reasons why an eccentric butterfly valve may be preferred over other valve types:
- Bubble-tight sealing with minimal torque required. The eccentric design enables secure sealing even at high pressures without excessive wear.
- Lower pressure drops and greater capacity. The disc rotation method allows more graduated throttling for optimized flow control.
- Handles corrosive and hazardous media. Provides tight shutoff to safely contain dangerous fluids.
- Compact size and light weight. Eccentric valves are smaller than other valve types with the same rating.
- Low maintenance and long service life. Durable seals and precision engineering allow a long working life.
- Fast and easy automation. The eccentric design allows easy actuation for remote control or automation.
- Cost effective. Eccentric butterfly valves offer performance at a lower price point than other advanced valves.
Applications for Eccentric Butterfly Valves
Eccentric butterfly valves provide reliable throttling, shutoff, and control across many industries:
- Chemical and petrochemical processing – For corrosive media transfer and containment.
- Water and wastewater management – For flow regulation in treatment plants.
- Pulp and paper manufacturing – For controlling bleach, acids, and process fluids.
- HVAC and energy systems – For handling hot/chilled water and steam.
- Mining and mineral processing – Slurry flow control and isolation of abrasive media.
- Food and beverage production – Regulating process fluids while maintaining sanitation.
- Pharmaceutical manufacturing – Strict isolation of sterile ingredients and fluids.
With their precise flow control, tight shutoff seal, and durable operation, eccentric butterfly valves are designed to excel in the most demanding industrial applications. Their offset disc eliminates the drawbacks of concentric valves for a superior performing solution. If your process depends on reliable fluid handling, be sure to consider the unique benefits of the eccentric butterfly valve.