Butterfly valves are quick opening and easily turning valves. They can be used for on or off applications but are usually selected for their threshold abilities. The butterfly valve is simply designed among all other valves. Compare to all other valve types butterfly valves have fewer working parts that can be easily repaired and used.
A butterfly valve that can be used for isolating or regulating fluid through a pipe. Their closing mechanism takes a form of a disc. Its operations are very much similar to other valves like slurry gate valve and knife gate valve, which are allowing it quickly to shut off. Butterfly valves mostly preferred as they are very low in cost as compare to lined butterfly valves or knife gate valves. It is also very lighter in weight compare to slurry gate valves. So it requires less support. In this disc take the center position in the pipe. The disc is connected to an accelerator in the outside or the upper side of the valve. The accelerator tries similar or vertical to the drive different with knife gate valves. Therefore, pressure always drop induced in the flow. In process the valve is completely opened or close when disc is taking a turn. The butterfly valves is a kind of metal disc molded continuously the Rod, when the butterfly valve is closed the disc is turned so depth that it totally blocks off the passage way, even at the butterfly valve is completely opened and the butterfly disc is rotated to so depth that it allows all the passage of the flow.
Types of butterfly valves:
- Concentric centerlines
- Single offset
- Double offset
- Triple offset
- Wafer butterfly valves
- Lined butterfly valves
- Lugged butterfly valve
Working of a butterfly valve:
It is very different from other valves both in structure and working mechanism. It uses a rounded plate or wafer functioned by a wrench to control the system flow similarly when we talk about the degree so it turn to 90 degree and the wafer ruins in the stream flows and rotate around the shaft connecting to the wrench. As the valve is being closed, the wafer rotate to become perpendicular to the direction of the flow and act as a dam to reduce or stop the flow. When the wrench is rotating back to the original position the wafer align itself in the direction of the flow and allow the commodity to pass through the valve but it has minimum turbulence and pressure drop. They are good for on/off and throat link services. It perform well, when good amount of liquid and gases are being passed through it. Their walls are not normally create a tight bonding so they must be used under low pressure and situation.
Advantages:
- It is easy to install and operate.
- It is affordable and manage friendly and convenient to repair.
- It can transfer mud in the pipeline outlet.
- It is good at low pressure.