Ball valves and butterfly valves have a lot in common. Both are quarter-turn valves, which makes them easy to open. Both are quite popular because of their simple designs and low cost. Because of these factors, it might be hard to choose which one is best for you. In this article, you are going to know the difference between the ball valve and the butterfly valve to help you make an intelligent choice.
Ball Valve
The ball valve is characterized by a sphere-like disc encased in a globe-like valve body. This sphere disc is hollow, that with a turn of a lever or handwheel by only 90 degrees, it opens to pass the media through, or closes to prevent the media from doing so. Ball valves are known to have low-pressure drops.
Butterfly Valve
The butterfly valve is a compact valve with a wafer-like disc that acts as a barrier when the disc is closed. Also, it only takes a quarter turn for this valve to open. Used for low pressure and low-temperature flow systems, the butterfly valve is also lightweight and has a short face-to-face dimension. The working mechianism of buttefly valve is also different from the ball valve. The following are the main difference between the two valves.
Ball Valve vs. Butterfly Valve
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Application
Sealing effectiveness affects how these valves are being used in services. Since ball valves can seal better, these can be used in critical applications where issues on contamination is a priority. Also, gas applications are well-suited for ball valves, especially the low-pressure type. The ball valve has a wide variety of ANSI classes. It can also handle extremely cold temperatures such as those used in cryogenic industries.
On the other hand, butterfly valves are more cost-effective and do not occupy too much space in the plant, these are used in water services where there is a need to control the flow of media. Since they are more economical to build, these valves are used in large scale projects.
Butterfly valve suppliers often follow the ANSI Class 150 rating. It means the valves can handle up to 285 psi with temperature ranging from -200F to 1000F
Function
Ball valves are used only for isolation. Ball valves are known for their bubble-tight shutoff. Rarely would you see a ball valve used as a control valve because the soft elastomeric seats get damaged easily in this condition.
When the ball valve is open, there is very little interference from the valve parts, hence, there is a little pressure drop. These valves are precise when used in high-pressure applications. There is no need for a pressure balancing scheme to equalize internal pressure.
Butterfly valves can act as isolation and control valves. But these don’t provide a bubble-tight shutoff. For this valve to be a great throttling valve, it needs the media should be slow-moving to avoid friction brought by the fast velocity of the media.
Also, there is a substantial pressure drop in the linear pressure when the butterfly valve is open. The disc is always in contact with the media as it flows. This results in a change in pressure.
For larger butterfly valves, a by-pass valve may be installed to compensate for the balance of pressure. Additionally, larger butterfly valves may need pneumatic or electronic actuation as these valves are difficult to manually open.
Structure
The ball valve has a hollow sphere-like disc inside the valve body. The ball valve The butterfly valve has a thin disc with a relatively thin body.
Conclusion
Bal valves and butterfly valves are inexpensive, practical and last long. Which one to pick depends on the nature of your projects. Butterfly valves in America is also in good quality and can also consider some nice manufacturers. Contact a highly dependable valve manufacturer for assistance when choosing the right kind of valve. Or you can also get the great manufacturers in this complete valve manufacturers guide in China.