The butterfly valves are defined as a type of flow control devices which are used to regulate the flow of liquid through a section of a pipe. The operation of these valves is similar to that of the ball valves. In a butterfly valve, a disc is positioned in the center part of the pipe. This disc is connected with the actuator present in the outside with the help of a rod. So when the actuator is rotated, it will result in movement of the disc either in parallel or perpendicular direction to the flow of liquid. The difference between the ball valve and the butterfly valve is that, in here, regardless of the position of the valve, disc will always remain within the flow in order to induce a pressure drop.

Operation of butterfly valves

These butterfly valves belong to quarter turn valves. Here the term butterfly refers to the disc or plate inside the valve which is mounted on the rod. When this valve is closed, the disc will be turned in way to fully block the flow of liquid. When the valve is open, the disc will be swiveled to a quarter turn and thus in turn will allow the passage of liquid. The butterfly valve may also be opened gradually in order to control the flow of liquid.

Types of butterfly valves

There are usually many kinds of butterfly valves and each kind is designed to meet a particular pressure requirement or usage. The common types may include the resilient butterfly valve and high performance butterfly valve. The resilient butterfly valve has the lowest pressure rating and it uses the flexibility of the rubber materials. On the other hand, a high performance butterfly valve is used for high pressure systems. The advantage of these valves lies in the slight offset in the way of disc positioning. This helps to completely seal the passage way when the valve is closed and getting less possibility to damage. There are also some other butterfly valves like tricentric butterfly valves which are able to withstand large amounts of pressure.