The Guide to Flanges – 2 Important Things to Know

A flange is defined as an internal ridge or external ridge that helps add strength, such as a flange of an I-beam. It also is used for an attachment to secure another piece onto an object, such as a flange on the end of a pipe or a flange of a rail car.

Flanges allow for easy cleaning, modifications and inspections. Flanges are most commonly screwed or welded on. To make a flange joint, two flanges are secured to each other with bolts and a seal is made by inserting a gasket between the two flanges.

What are the most commonly used flanges?

The most commonly used flanges are welding neck flanges, socket weld flanges, slip on flanges, threaded flanges, blind flanges and lap joint flanges. Special custom flanges also exist, such as an orifice flange, an expander flange and a long welding neck flange.

Flanges come in an array of materials, including stainless steel, aluminum, cast iron, bronze, brass and plastic. There are several manufacturers of flanges and other forging components, such as ASME forging components.

Standards for Flanges

Standards for flanges are different for each country. A flange manufactured in the United States will not be interchangeable with one produced in Japan. Flanges are also separated into different pressure classes. This means certain flanges can handle more pressure than other flanges.

Two examples of common household objects that incorporate a flange are a vacuum cleaner and a microwave. Ski boots also commonly use a flange at the heel to attach the boot to the binding of the ski.