As you probably already know, a butterfly valve is a quarter-turn valve with a disc-shaped seat. The disc is perpendicular to the fluid when the valve is closed and parallel to the fluid when the valve is open. These valves are lever-operated, gear-operated or mechanically/pneumatically actuated. While the operation of butterfly valves is simple, most people are unaware of the different types of butterfly valves that exist.

With the choice of butterfly valves, such as different body types, materials and methods of operation, there are many types of butterfly valves to choose from. First, let’s examine the different body types, and then talk about the materials and how to do it. These factors tell you what the valve does. Choosing a butterfly valve for your application can be difficult, so we’ll try to make things easier with this blog post!

Butterfly valve body type
Butterfly valves are popular for their low profile design. They are thin and usually take up much less space in the pipeline than ball valves. The two main variants of butterfly valves differ in how they are attached to the pipe. These body styles are lug and wafer styles. What is the difference between lug and wafer butterfly valves? Read on to find out.

The lug butterfly valve (shown below) acts much like a true union ball valve. They allow adjacent pipes to be removed while the system is still running. These valves do this by using two different sets of bolts, one set to each adjacent flange. The remaining set of bolts maintain a firm seal between the valve and a pipe. Lug butterfly valves are ideal for applications that require regular cleaning and other maintenance.

Lug type pvc butterfly valve

Wafer-style butterfly valves (shown below) do not have the extensive bolting that makes lug BF valves obvious. They usually only have two or four holes to hold the valve and align it with the pipe. They fit very securely, often giving them twice the pressure rating of comparable lug-style valves. The main disadvantage of wafer butterfly valves is that they are not as easy to maintain as male valves. Any maintenance in or around the disc butterfly valve requires shutting down the system.

Wafer type pvc butterfly valve

Each of these butterfly valve options has its own advantages, so choosing one depends on what you need it to do for you! We’ve looked at the different body types available, but what are our material choices?

Butterfly valve material
Like other types of valves, butterfly valves come in a variety of materials. From stainless steel to PVC, the options are basically limitless. However, there are some materials that are particularly popular, so let’s take a look at them!

PVC and cast iron are used for different types of butterfly valves PVC is one of the most common plastics for butterfly valves. A few qualities make them ideal for many low to medium strength applications. First, they are lightweight while still having impressive structural integrity. Second, they have broader chemical compatibility than most metals. Finally, both PVC and CPVC are relatively inexpensive compared to their metal counterparts. Click the link to view our wide range of PVC Butterfly Valves or CPVC Butterfly Valves!

Cast iron is the metal of choice for butterfly valves. Cast iron has a greater structural integrity and temperature range than PVC or CPVC, making it an excellent choice for industrial processes that require more robustness. Among metals, iron is an inexpensive option, but that doesn’t mean it’s ineffective. Cast iron butterfly valves are versatile and therefore ideal for a variety of applications. Our parent company Commercial Industrial Supply provides butterfly valves for industrial applications.

How to Operate Different Types of Butterfly Valves
The method of operation also distinguishes butterfly valves from one another. The two manual methods are handle and gear. Depending on the model, automatic drive is also possible! Lever-style butterfly valves use a quarter-turn lever (usually with a locking mechanism) to turn the valve stem, opening and closing it. This is the simplest form of BF valve operation, but is impractical and difficult for larger valves.

Geared Butterfly Valve Geared operation is another common method of opening and closing butterfly valves! The manual wheel rotates a gear attached to the valve stem to move the disc. This method works for all different types of butterfly valves, big or small. Gears make the operation of butterfly valves easier by using a mechanically intuitive method to turn the disc rather than just manual labor.