At their points of connection, all PVC pipes have rims. These rims are either built into the pipe as an outer lip or inner lip. In some cases however, the rim can be added externally using PVC Flanges. In order to provide uniformity in size, within the Americas the standard PVC flange size was determined by ASA/ANSI. These flanges are then classified further by the pressure they can withstand. The pressure rating will depend on the material the flange is made of as well as what material the flange is interacting with.

In addition to varying widely in size and pressure ratings, flanges have a wide range of shape as well. Available shapes are raised, flat, tongued and grooved, or ring joint form. Some other shapes exist, but the five above are the most commonly used of the flanges.

Pipe flanges are generally one of six design types: weld neck, slip on, blind, socket weld, threaded, or lap-joint. All of these types of pipe flanges can be found in the easy to use shapes of rectangle, square, or circle. A closet flange is a good example of a round flange shape. Closet flanges are applied to the pipe to provide a rim or lip to fasten onto connecting pipe. A rarer type of flange known as the blind flange is also round in shape, but will cover the pipe face like a plate; essentially ending the flow there.

For more information please see our Flange Installation Data Sheet.