A butterfly valve is a quarter-turn valve that controls fluid flow within a piping system. Its name comes from the thin, disc-shaped closure mechanism that rotates around the valve shaft to regulate flow. When the valve is fully open, the disc is perpendicular to the flow, allowing maximum fluid passage. Conversely, when the valve is closed, the disc is parallel to the flow, blocking it completely.
Butterfly valves are known for their simple design, compact size, and quick operation. They are often used in large-diameter piping systems, where space and weight are significant considerations. Typical applications include water treatment, HVAC systems, power generation, and industrial processing.
These valves come in various designs, including wafer, lug, and double-offset configurations, each offering unique benefits in pressure rating, sealing capability, and ease of installation. Depending on the operating conditions and fluid properties, the materials of construction range from cast iron and ductile iron to stainless steel and exotic alloys.