Everything that you need to know about Flanges

What are flanges for piping?

Various industrial undertakings require use of pipes in order to transport raw materials or end products. The pipes consist of an entire set-up that we acknowledge as a piping system. This apparatus accommodates a variety of parts that are used to connect different pipes, pumps and valves to other components that will create a system which will ensure uninterrupted flow of contents. Flanges are that one integrant which connects different pipes and other constituents. They provide a fail-safe method for integration to an array of industries worldwide. Apart from joining, flanges offer easy dismantling and access in order to provide hassle-free maintenance of the whole network.

A flanged connection usually has

  • Flanges
  • Gasket
  • Bolting

Types of flanges

According to the usage, let us have a look at the most common types of flanges readily available with flange manufacturers

  • Threaded or screwed

Such sort of a flange has a threaded bore body which will complement the thread on pipe or it’s fitting. This eliminates the hassle of welding unnecessarily.

  • Weld flange

Socket-weld is a type where the pipe is connected to the flange with the help of  fillet weld. It is intended for use with low pressure and temperature.

  • Blind flange

These are essentially discs which can be bolted. They are used at the break off points of piping systems to achieve a seal.

  • Lap joint

These contain two segments which are joined with a butt-weld for installation.

This is the only flange which is provided with a flat face.

  • Weld neck

Used in the systems with multiple angles and turns because of their excellence to withstand them, they too need a butt-weld alike lap joint flanges.

  • Slip-on

The most commonly used one since it has high tolerance to heavy flow and pressure.

They are welded to pipes or fittings in order to secure them.

  • Special flange types

Apart from the ones that are used most commonly along with extensive availability, there are certain flanges which we use for specialized operations.

They are namely:





Long neck

In order to select the right flange, it is utterly important to pair the particular design of the flange in accordance with the pipes and fittings so as to ensure longevity and durability of entire framework.

Now let us have a look at How to select the ideal flange for piping system:

First and foremost thing that you need to consider is suitable flange type. However, it is not the only factor. One of the determining characteristics is type of facing. Face type also decides about gaskets needed.

Different face types are

  • Flat facing

As the name suggests, surface of this type is even to accommodate gasket in its entirety

  • Raised facing

It has elevation around its bore to fit a circle gasket inside it.

  • Male and female

It contains complementing elements where one part has grooves while another contains elevated portions both of which fit into each other. Female part retains gasket.

  • Ring joint type

Used in extreme conditions, this mainly lodges gasket in its groove to create a seal.

  • Tongue and groove

As name implies, such facing has a grooved and a raised part which functions as firm retainer when seated into each other.

They are further categorized as serrated and smooth flanges.

Choosing right type of facing from flange supplier is essential for purpose of impeccable gasket selection and hence the seal.

What are the other variables to make allowances for while choosing an ideal flange?

  •  Outer diameter of flange
  •  Outer diameter of pipe corresponding to flange
  •   Inner bore diameter
  •   Thickness of the outer rim
  •   Bolt circle diameter

 Which materials are used by flange manufacturers ? 

There is wide range available keeping in mind to cater to various intended  uses, temperatures and pressures. They can be tailored from stainless steel,forged carbon steel, aluminium, brass, bronze and several alloys Monel, Inconel, Chrome moly and so on.

Stainless steel alloys are broadly used as it can sustain high pressure conditions which makes it the best pick for transiting pressurized gases and Liquids.

There is something called ‘lined flanges’ which are lined with material different from flanges themselves. They are internally customized for specific    purposes and consequently, flange material would differ from pipes and fittings.

How do we recognise the right flange based on our need?

Flanges are selected along with pipes and fittings. You will be easily able to figure out whether it is up to the mark or not as they are classified based on their temperature and pressure tolerance.

Usual classifications are

  1. 150#
  2. 300#
  3. 600#
  4. 900#
  5. 1500#
  6. 2500#

How do we verify the product?

Industries get their orders customized from flange exporters quite a times.

Thankfully, flanges are globally standardised by ASME.

You can find a trademark on outer rim with all important information inscribed such as manufacturer code,       material grade, size, ASTM code and so forth.