Butterfly valves, as you may already know, are a type of quarter-turn valve with disc-shaped seatings. The disc sits perpendicular to flow of when the valve is closed and parallel to flow when the valve is open. These valves are handle-operated, gear-operated, or mechanically/pneumatically actuated. While the operation of butterfly valves is straightforward, most people do not know about the different types of butterfly valves that exist.
With butterfly valve options such as different body types, materials, and operation methods, many types of butterfly valves are available. First, let's examine the different body types, then move on to materials and operation methods. These factors tell you what the valve is capable of. Choosing butterfly valves for your application can be difficult, so we will attempt to make it easier with this blog post!
Butterfly Valve Body Types
Butterfly valves are popular because of their low-profile designs. They are thin, usually taking up much less space in a pipeline than ball valves. The difference in the two main variations of butterfly valves is how they attach to the pipeline. These body styles are lug and wafer style. What's the difference between lug and wafer style butterfly valves? Keep reading to find out.
Lug style butterfly valves (shown below) act much like a true union ball valve. They allow either of the adjacent pieces of piping to be removed while the system is still in operation. These valves do this by using two different sets of bolts, one attaching to each of the adjacent flanges. The remaining set of bolts keeps a strong seal between the valve and one piece of piping. Lug butterfly valves are perfect for applications where cleaning and other maintenance needs to be done regularly.
Wafer style butterfly valves (shown below) do not have the multitude of bolt mounts that make lug BF valves obvious. They usually have just two or four holes to secure and align the valve with the pipeline. They sit very securely, typically giving them twice the pressure rating of comparable lug-style valves. The major downside of wafer butterfly valves is that they do not allow easy maintenance like lug valves. Any maintenance in or around a wafer style butterfly valve requires a system shutdown.
Each of these butterfly valve choices has its own strengths, so choosing one depends on what you need it to do for you! We have looked at the different body types available, but what are our material options?
Butterfly Valve Materials
Like other types of valves, butterfly valves come in a wide range of materials. From stainless steel to PVC, the choices are basically limitless. A few materials are especially popular though, so let's take a look at them!pvc and cast iron for different types of butterfly valvesPVC is one of the most common plastics for butterfly valves. A few qualities make them ideal for many moderate-to-low intensity applications. First, they are lightweight while still possessing impressive structural integrity. Second, they have wider ranges chemical compatibility than most metals.
Finally, PVC and CPVC are both inexpensive compared to their metal counterparts. Check out our wide range of PVC butterfly valves or CPVC butterfly valves by clicking the links!
Cast iron is a go-to metal for butterfly valves. Cast iron has considerably more structural integrity and temperature range than PVC or CPVC, which makes it a great option for industrial processes that require something tougher. Among metals, iron is the inexpensive option, but this does not make it ineffective. Cast iron butterfly valves are versatile, which makes them perfect for a wide range of applications. Our parent company Commercial Industrial Supply carries butterfly valves for industrial applications.
