A 3-way butterfly valve is a type of flow control valve that is used to regulate the flow of a fluid in a piping system. It is designed with three ports, two of which are inlet ports and one is an outlet port. The valve is designed with a disc-shaped butterfly plate that rotates within the valve body. The butterfly plate has a hole in the center that allows the fluid to pass through. Depending on the position of the butterfly plate, the valve can be used to control the flow of the fluid from one inlet port to the other, or from both inlet ports to the outlet port. This type of valve is commonly used in applications such as water treatment, chemical processing, and food processing. It is also used in industrial applications such as oil and gas production, and in HVAC systems. The 3-way butterfly valve is a versatile and cost-effective solution for controlling the flow of a fluid in a piping system.