We're closed today.
News 18.11.2020

Butterfly valves: Difference between Wafer and Lug

Socla Wafer-style butterfly valve

Wafer type

+ Lighter
+ Easy installation

- Pipe flanges required
- More difficult to centre
Not suitable as end valve

In the case of a Wafer-style butterfly valve, the body is annular with a few non-tapped centring holes. Some Wafer types have two while others have four.

The flange bolts are inserted through the bolt holes of the two pipe flanges and the centering holes of the butterfly valve. By tightening the flange bolts, the pipe flanges are pulled towards each other and the butterfly valve is clamped between the flanges and held in place.

Socla Lug-style butterfly valve

Lug type

+ Suitable as end valve*
Easier to centre
Less sensitive in case of large temperature differences

- Heavier with larger sizes
More expensive

In the case of a Lug-style butterfly valve  there are so-called "ears" over the entire circumference of the body into which threads were tapped. In this way, the butterfly valve can be tightened against each of the two pipe flanges by means of 2 separate bolts (one on each side).

Because the butterfly valve is attached to each flange on both sides with separate, shorter bolts, the chance of relaxation through thermal expansion is smaller than with a Wafer-style valve. As a result, the Lug version is more suitable for applications with large temperature differences.

*However, when the Lug-style vavle is used as the end valve, one should pay attention because most Lug-style  butterfly valves will have a lower maximum allowed pressure as the end valve than their "normal" pressure class indicates.

Butterfly valves at Fluxer

These two types of butterfly valves are available in all kinds of different designs. You can choose a fully manual butterfly valve, a pneumatic operated one, with gearbox or electric motor. What the difference is between these versions we will keep for a later news item.

More news?

Stay up-to-date and receive future announcements directly in your mailbox. Spam free.

This form can only be sent with the use of technical cookies. You can accept these cookies here.
These cookies are used to distinguish people from bots. Certain data, such as your IP address or language preference, can be sent to Google. For more information about our cookie policy. If you don’t want these data to be processed by Google, you can send your question or request to sales@fluxer.be.