Butterfly Valve

A butterfly valve is a type of valve used to isolate or regulate the flow of a fluid in a piping system. 

Structure

It mainly consists of a valve body, a valve stem, a disc, and a sealing ring1. The valve body is made of tough and rigid materials and houses and protects the internal components. The disc, which is the key component for controlling fluid flow, is mounted on the valve stem. The sealing ring provides sealing between the disc edge and the valve body when the valve is closed.

Working Principle

The disc is positioned in the center of the pipe and rotates around an axis. When the disc is perpendicular to the flow direction, the valve is closed, completely blocking the fluid passage. When the disc is parallel to the flow direction, the valve is fully open, allowing the fluid to flow through with minimal resistance. Additionally, the disc can be rotated to an intermediate position to throttle the flow.

Advantages

Butterfly valves have several advantages, including low cost, lightweight, compact size, and easy installation1. They also have a relatively fast opening and closing speed and require low operating torque.

Disadvantages

One disadvantage is that there is always some pressure drop in the flow, even when the valve is open, because the disc is always present within the flow. In addition, butterfly valves may not be suitable for high-pressure and high-temperature applications, and their sealing performance may be affected by factors such as fluid pressure and temperature.

Applications

They are widely used in various industries such as petroleum, chemical, metallurgy, construction, and water treatment. In the petroleum and chemical industries, they are used for the control and cutoff of media in oil and gas transmission pipelines, storage tanks, and heating furnaces. In the water treatment industry, they are used for the control and cutoff of media in water treatment equipment such as sewage treatment plants and desalination plants.