What is a Raised face flange and a Flat faced flange?

Author: Kr Shelar

Flanges have been an integral part of the piping system. There are varieties of flanges that are in use in different industries. Every industry demands a special set of flanges according to their requirements.

Through this article, you will be familiar with the different range of flanges available; their sizes, shapes, advantages, demerits and use. Scroll down to know your flanges better.

What is a flange?

A flange is a metal disc used to join pipes. A gasket is fixed between the two flanges to tighten up the seal. A flange is used to connect two pipes or valves or tubes to form a piping network. Flanges provide support and strength and prevent leakage.

Flanges are commonly welded or screwed into pipes or valves and are then joined with bolts. Flanges provide easy access to clean or inspect a piping system.

What is a Raised faced flange?

A raised face (RF) flange is the most frequently used flange-type in process plant applications. It can be recognized easily as the gasket surface of the flange is raised above the bolting circle face. As a result, they are called ‘raised’ face flanges.

Use:

Raised face flanges enable the use of a range of gasket designs like flat ring sheet type, spiral wound and double jacketed.

Purpose:

The primary purpose of a RF flange is to distillate more pressure on a smaller gasket area; thereby increase the pressure containment capability of the joint.

What is a Flat face flanges?

A flat face flange is the opposite of a raised face flange, wherein the face of the flange is flat. These flanges hold a gasket in the same area as the bolting circle face. In a piping system, a mating flange or valve made of Cast Iron requires a flat face flange.

It is a norm never to mate a Raised face flange with a Flat face flange. It is always wise to use full-face gaskets with full faced flanges; the gaskets guarantee an entire and a regular contact between the two mating flanges.

For more information on Raised face and Flat face flanges, visit: http://www.ssflanges.net/