When it comes to finding the right valve for your marine or industrial job, ball and butterfly valves often take center stage.
Ball valves and butterfly valves have several characteristics in common, including:
They’re both quarter-turn rotary valves, requiring a 90-degree turn from open to close.
Both are typically made from a combination of cast iron, stainless steel and brass.
Each valve is effective for regulating the flow of most types of gas and liquid at a wide range of temperatures.
They both are relatively inexpensive, long-lasting and dependable.
Ball valves and butterfly valves are both easily available through a valve distributor.
With so many similarities, you’ll have to look at their differences to determine which type of valve would work best for a specific project. Here’s a look at how ball valves and butterfly valves differ from one another and how it affects their uses:
Design
Generally speaking, a ball valve is a ball with a hole through it. A butterfly valve generally consists of a disk mounted on a rotating shaft.
Functionality
When using a ball valve, turning the valve handle moves the hole in the ball to either block, partially block or open the flow of gas or liquid through the valve. When using a butterfly valve, turning the valve handle turns the disk 90 degrees to either fully open or fully block the flow of gas or liquid through the valve.
Pressure
One of the advantage of a ball valve is that it will almost always turn, regardless of the amount of pressure being placed on it from the supply side. Once open, there is rarely a drop in pressure because the hole in the ball allows 100 percent of the gas or liquid to flow.
Butterfly valves are built so that part of the disk is always interfering with the flow of the liquid or gas. This means there will always be a pressure drop when using a butterfly valve. It also means that butterfly valves can be difficult to open and a bypass valve may be necessary to create balance in the lines before large butterfly valves can properly operate.
Uses
Ball valves seal more effectively than butterfly valves, so ball valves are generally better for projects involving the flow of gas. Butterfly valves are generally less expensive to build and maintain, so they’re frequently used in large-scale municipal water and sewer projects.
They are also common for projects that control the flow of river or stream water.
Finding the right valve for the right project
Ball valves and butterfly valves are both versatile, relatively inexpensive and able to stand the test of time. Which one is right for which project depends on the size and scope of the task. For help determining whether a project calls for a ball valve, a butterfly valve or another type of valve, contact a qualified valve distributor today.
