Butterfly Valves

Butterfly valves are a type of quarter-turn valve used to control the flow of fluid within a piping system. They are named for their disc, which is mounted on a central shaft and resembles the wings of a butterfly. Butterfly valves are commonly used in a wide range of industries, including water treatment, HVAC (Heating, Ventilation, and Air Conditioning), chemical processing, and power generation.

Here are the key features and components of butterfly valves:

Body: The body of a butterfly valve is typically made of metal, such as cast iron, ductile iron, stainless steel, or aluminum, although some valves may have bodies made of plastic or composite materials. The body provides connection points for the pipeline and houses the internal components of the valve.
Disc: The disc is the main component of the valve that controls the flow of fluid. It is mounted on a central shaft and positioned in the flow path within the valve body. When the valve is open, the disc is turned parallel to the flow direction, allowing fluid to pass through. When the valve is closed, the disc is rotated perpendicular to the flow direction, blocking the flow of fluid.
Seat: Butterfly valves have a seat or sealing surface around the perimeter of the valve body against which the disc seals when the valve is closed. The seat is typically made of resilient material, such as rubber or synthetic elastomers, to provide a tight seal and prevent leakage.
Stem: The stem is the mechanism that connects the actuator to the disc. When the actuator is operated, it rotates the stem, which in turn rotates the disc to open or close the valve.
Actuator: Butterfly valves can be operated manually using a hand lever, gear operator, or wrench, or they can be automated with pneumatic, electric, or hydraulic actuators. These actuators provide the force necessary to rotate the disc and operate the valve remotely.

Butterfly valves are known for their quick operation, low pressure drop, and compact design. They offer good flow control characteristics and are suitable for a wide range of applications, including on/off and throttling service. However, they may not provide as tight a seal as other types of valves, such as gate valves or globe valves, particularly in applications requiring bubble-tight shut-off.

Overall, butterfly valves are versatile, cost-effective, and widely used in various industries for controlling the flow of fluids in piping systems. They are particularly well-suited for large-diameter applications where space and weight considerations are important.