butterfly valve

A butterfly valve is a type of flow control device used to regulate or isolate fluid flow in pipelines. It consists of a circular disc (the "butterfly") mounted on a rotating shaft. When the valve is fully closed, the disc blocks the flow; when fully open, the disc is rotated a quarter turn to allow flow through the pipe.

Butterfly valves are compact, lightweight, and quick to operate (usually requiring just a quarter turn). They're commonly used in industries such as water supply, wastewater treatment, chemical, and HVAC due to their reliability and cost-effectiveness.