5 Different Types of ANSI Flanges

Large diameter flanges

In case this is the first time you’re hearing the phrase, ANSI flanges simply refers to flanges whose construction meets ANSI (American National Standards Institute) specifications. These may be either smaller or large diameter flanges and as you would expect, there are a variety of different styles used by process engineers across a wide range of industries. Keep reading for brief descriptions of the most common types of ANSI-compliant flanges.

Threaded Flanges

Threaded flanges are a very popular choice, since they can be easily integrated into an assembly without requiring welding. Their threaded design also allows for them to be salvaged and reused when an assembly is dismantled, provided the flange is otherwise in good condition.

Slip On Flanges

These are often chosen for applications where no disassembly is anticipated, since these ANSI flanges are welded into place. Despite the fact that welding is required, they are considered to be one of the easier types of flanges to properly fit and align.

Blind Flanges

A blind flange is most often used in applications, which require stopping up the end of a flanged pipe, pressure vessel or valve. As the name implies, these ANSI flanges do not feature an outlet.

Lap Joint Flanges

These ANSI flanges differ from other styles in that their use requires an end connector; the pipe, valve or other product to be connected with the flange does not come into physical contact with it. However, this type of flange assembly allows for the rotation of the flange and makes it well suited for applications where the assembly may need to be dismantled relatively frequently for cleaning and maintenance.