What Is a Butterfly Valve?

It's important to understand each kind of valve and how they operate to select the best one for your plumbing installation. It would help if you familiarized yourself with butterfly valves. You've likely heard of this type of valve, but do you know anything about it? Do you even know what is a butterfly valve?

How Do Butterfly Valves Work?

A butterfly valve is named for the rotating disc that opens and closes the valve. They are cheap, lightweight, and are capable of quick shut-off. The disc operates with just a quarter turn on the rod that secures it, which means that it's in the way a little bit when the valve is open. This results in a slight pressure drop. You can also partially open a butterfly valve, which allows you to control different flow rates.

Butterfly Valve Diagram

Here is a quick-reference butterfly valve diagram for easy understanding:

what is a butterfly valve diagram

Types of Butterfly Valves

Typically, when people talk about the type of butterfly valve, they mean the shaft's alignment relative to the body centerline.

  • Concentric: shaft and body centerline align perfectly. Usually made of a resilient rubber seat and a standard metal disc.
  • Double-eccentric: this means the shaft is offset from the body centerline and the pipe centerline. It's a high-performance valve made of a variety of materials.
  • Triple-eccentric: this means the shaft is offset from the body centerline, the pipe centerline, with a conical shape offset shape on the seal. They are typically made with a laminated or metal seat design.

There are also different manners in which they operate. There are wafer-style valves, lug-style (installation type), and rotary valves (which you likely wouldn't use for plumbing).

Save on Butterfly Valves at PlumbersStock

Now that you've learned the basics, you should be ready to proceed with your project. The next step is choosing your butterfly valve. No matter what you need, you'll be able to find the right plumbing valve here at PlumbersStock.com. If you have trouble navigating the site, please don't give up. Just contact us because we probably have the best valve for the job. For contractors or homeowners buying bulk, hit us up about special deals.

Related resources:
Gate Valve vs. Butterfly Valve
Butterfly Valve vs. Ball Valve
What Is a Check Valve?
What Is a Ball Valve?
What Is a Gate Valve?
What Is a Globe Valve?
What Is a Curb Stop?

Shopper Award