Butterfly Valves

Butterfly valves are a type of flow control device used extensively in water and wastewater treatment plants. They allow for quick shut-off or modulation of water flow through a pipeline. These valves work by rotating a disc, the "butterfly", which is centrally positioned within the pipe. When the disc is turned to a parallel position in relation to the flow, the valve is fully open. When the disc is rotated to a perpendicular position, the valve is closed.

• Influent and effluent lines for controlling the flow of water into and out of treatment processes.
• In distribution systems for isolating sections of pipeline for maintenance or during emergencies.
• In sludge handling systems for controlling the flow of solids.

• Regular inspection for leaks or signs of wear.
• Occasional lubrication of the valve stem.
• Periodic testing of the valve's operation.
• Safety considerations mainly involve ensuring that the valve is not abruptly closed or opened, which could cause water hammer or damage the valve.

• Disc: This is the main component that regulates the flow of fluid. Its size, shape, and material can affect the valve's performance and lifespan.
• Stem: Connects the disc to the actuator. It rotates the disc to open or close the valve. The stem material must be corrosion-resistant.
• Body: The main casing that houses the disc and stem. It's often made from cast iron, stainless steel, or other durable materials.
• Seat: The part of the valve body that the disc seals against when the valve is closed. The seat material must be chosen for its sealing ability, resistance to wear, and compatibility with the fluid.

• Pipeline diameter (in inches or millimeters)
• Maximum flow rate (in gallons per minute or liters per second)
• Maximum operating pressure (in pounds per square inch)

• MasterFormat Division 44 - Pollution and Waste Control Equipment, Section 44 05 13 - Process Control Butterfly Valves.

• DeZURIK: BHP High Performance Butterfly Valves
• Bray: Series 20/21 Butterfly Valves
• Flowserve: Durco Big Max BX2001

• Ball Valves: Like butterfly valves, ball valves provide quick shut-off but tend to have better sealing properties. They might be preferred in systems where tight shut-off is critical.
• Gate Valves: These are best suited for systems where flow needs to be fully on or fully off, rather than modulated. They are generally more expensive and slower to operate than butterfly valves.