If you check with trusted valve distributors for butterfly valves, they’ll have several selections. For instance, you’ll find both lug and wafer type valves but what’s the difference and which one should you use for your applications? Here is important information on lug and wafer butterfly valves, to help you make the best decision.
Defining Butterfly Valves
A butterfly valve has a round disc in the center of the mechanism. When you turn the handle, it rotates the disc. If you turn the disc one way, it closes off the flow. This is the “off” position. Turn the disc the other way, and the valve is fully “on.” Butterfly valves are often used for flow regulation so you can use them partly open or closed, and it won’t cause problems like chattering. Chattering is a thumping sound which some valves (like gate valves) can make when they are partly closed.
Valve distributors should have a large supply of wafer valves because they are the most popular type. In fact, many people consider wafer type valves the “standard” when it comes to butterfly valves. When you order butterfly valves from valve distributors, they may assume you mean wafer valves.
Installing Wafer Valves
When you install wafer type butterfly valves, you have to disconnect both sides of the piping and shut down the system.
Lug style butterfly valves are similar to ball valves. Their unique design makes it possible to install them by only disconnecting one side of the system. They have flanges with threaded inserts and lugs (not nuts). You have bolts on each flange. The easy installation feature makes lug-style valves the better choice if you need to clean, repair, or inspect the valve because you don’t have to shut off the entire system. If you’re not sure about your choices, your local valve distributors are there to help.