A butterfly valve is a flow regulating disc valve. A butterfly valve is a valve in which the obturator rotates about an axis at right angles to the direction of flow and, in the open position flow passes around the obturator.

In other words, a butterfly valve consists of a circular disc or plate built with a stem through the middle or attached offset. When opened, the disc pivots 90 degrees in the valve bore, aligning with the flow, creating a nearly unrestricted flow path. Butterfly valves operate similar to ball valves in their 90 degree rotation and allow for quick shutoff.

Butterfly valves Suppliers have gained popularity over the years due to their thin profile between flanges, making them lighter in weight and creating a smaller install footprint. This compact design also usually makes the initial cost for these valves lower when compared to other valve designs.

There are different types of butterfly valves and each type has unique design features and applications. Each type is defined by the orientation of the stem to the disc and the seating angle that the disc closes on.

The most basic butterfly valve design is commonly called a concentric or resilient-seated butterfly valve. In this type of valve, the stem is centered in the middle of the valve disc, which is centered in the pipe bore. This valve typically has a rubber (or resilient) seat and relies on the disc having a high level of contact with the seat to effect a seal.