What type of butterfly valve connection is most commonly found?

The most commonly found type of butterfly valve connection is the wafer design. This design is widely used due to its simplicity, compactness, and ease of installation between flanges. The wafer-style butterfly valve has a disc that rotates to open or close the flow of fluid, and it is typically installed between two pipe flanges without the need for additional flanges on the valve itself.

This connection type is advantageous in various applications because it fits into standard flange spacing, making it suitable for space-constrained installations. Additionally, wafer butterfly valves often have a reduced face-to-face dimension compared to their flanged counterparts, which can be beneficial in systems where space is limited.

In contrast, single and double flanged designs are less common for butterfly valves, as they may require additional components and can be bulkier. They do provide certain benefits in terms of securing the valve but are not as frequently used in standard applications, which contributes to the wafer design's popularity in the industry.