Skip to content

What are the Main Elements Of The Flange?

A flange is an extension of a structure and usually has holes drilled into it, usually with a flared or angled end to form a joint. These holes are placed in the flange to accommodate securing bolts. The flange joins or seals the various parts of the structure.

Below are the main elements of most flanges in our supply scope:

Dimensions of Flanges

Each flange ASME B16.5 has many standard dimensions. If a draftsman in Australia, a work preparer in Japan, or a pipefitter in Canada is speaking about a Welding neck flange 6” – 150#-S40 ASME B16.5, the spec goes over the flange dimensional details established.

If the flange is ordered, the supplier wants to know the material’s quality. For example, ASTM A105 is a forged carbon steel flange, while A182 is a forged stainless steel flange specification.

elements flange

Applications of flanges

The purpose of the flange depends on its design. It can help to increase the strength of the structure in the case of say an iron beam in structural steel. These are often useful in the construction of buildings and houses.

A flange can also be used as a guide to keeping a particular object in place. It is common in train wheels with flanges on either side to prevent the wheels from changing directions. The most common use of a flange is to help attach objects like pipes. With the use of these items, the pipes can be easily disassembled or assembled.

Pipe flanges raw material specifications

The usual materials of flanges include polymer/plastic, aluminum, carbon steel, and stainless steel.

1. Raw material

2. Material Inspection

3. Material Cutting

The choice of material depends on the flange’s purpose. For example, stainless steel flange is more durable and is crucial for heavy use in higher and colder temperatures. On the other hand, plastic is more feasible for use in the home because of its easy installation and reasonable prices.


The picture shows a serrated finish on a raised face. The face of the flange is usually designed to be a groove and tongue. It means that attaching two flat pieces to make one single surface. Another example of the design of a flange is the ring joint.

This type of flange covers the entire face, including the external and internal portions of the bolts. Another face of the flange is the raised face, wherein a part of the face of the flange is elevated around it to seal the flat gasket.

Flange design

One of the most common designs of the flange is the welding neck. It is meant to be used in welding tubing or pipe. Another example is the blind flange.

It is a type designed to have no opening in the center and is used to seal a connection or close it off. A threaded flange has an external or internal thread opposite to its ring groove. Its purpose is to match a standard threaded pipe.

General Flange standards

All flanges are manufactured following industry-accepted standards. Flanges usually follow standards set within the country. They are applied such as those set by the ANSI and API.

These standards make the dimensions of the flanges uniform so they can be interchangeable. However, a flange that follows the API or ANSI may not fit into the standards followed abroad.

Other flanges facings covered by these standards include small and large tongue-and-groove facings and the ring joint facing specifically for ring joint type metal gaskets.

Flange types

There are three types of flange types which are optional, integral, and loose.

Blind, lap-joint, socket weld, threaded, slip-on, welding neck flange follow standard types. You will be able to see that the flanges available in the type of flange are very similar to them. All the ‘pros’ and ‘cons’ described there can be applied here.

The types divide the flanges into three main groups: optional, integral, and loose. Here are the descriptions of these three types:

Loose type flanges

It is a type that covers designs in which the flange has no direct connection to the pipe wall, vessel, neck, and nozzle where the method of attachment is not taken into consideration to give the mechanical strength equivalent to the integral attachment.

Integral type flanges

This type covers designs where the flange is forged and cast integrally with butt welded, pipe wall or vessel, or nozzle neck.  They are attached by other forms of gas or arc welding of such a nature that the flange and nozzle neck, vessel, or pipe wall is considered equivalent to an integral structure.

Optional Type Flanges

The type covers designs where the attachment of the flange to the pipe wall, vessel, neck, or nozzle is such that the assembly is considered to act as a unit.


The above points explain the basic flange design and its main elements. However, remember that a wide range of flanges is available in the market. It is why it is impossible to list out every detail, configuration, and consideration.

If you have any further inquiries or want to know more about the main elements of the flange, contact Texas Flange today!

0 0 votes
Article Rating
Notify of
Inline Feedbacks
View all comments