What are Flanges and its types?

What is a Flange

Flange is a protruding ridge/rim, that is used to improve strength or distribute load. Flanges are used to connect valves, pumps, pipes & other equipment to form a piping system. It also allows for simple washing, inspection, and alteration. Flanges are welded or screwed together. Flanged joints are created by bolting two Flanges together and placing a gasket between them to form a seal.

When the piping joint needs to be dismantled, Flanges are used. These are often found in machines, valves, and specialty applications. Breakout Flanges are installed at regular intervals in many Pipelines where maintenance is a regular occurrence. A Flanged joint is made up of three different but integrated components: Flanges, gaskets, and bolting. Special controls must be used in the selection and application of all of these components to achieve a leak-proof joint.

Materials used for Manufacturing Flanges

Pipe Flanges are made of a variety of materials, grades. There are some materials that can be used to make Flanges. The most commonly used materials for Pipe Flange manufacturing are Carbon Steel, High Yield Carbon Steel, Alloy Steel, Stainless Steel, Duplex and Super Duplex, and various Nickel Alloy Grades such as Monel, Inconel, Hastelloy and Incoloy.

Different Types of Flanges

  • Slip-on Flanges

Because of their low material cost and ease of installation, Stainless Steel Slip-on Flanges are commonly used. There are several other diameters and low-pressure models to choose. Unlike Welding Neck Flanges, this Flange lacks a neck to rest on the Pipe, necessitating double welding.

  • Socket Weld Flange

Socket-welding Pipe flanges are generally used on low-diameter, high-pressure pipes. These Pipe Flanges are attached by inserting the Pipe into the socket end and adding a fillet weld around the top. This results in a smooth bore and improved flow of the fluid or gas within the Pipe.

  • Threaded Flanges

Threaded Pipe Flanges are flanges that can be secured to a pipe without the use of welding. Threaded flanges have an internal thread that connects to the pipe’s external thread. Threaded Pipe Flanges are identical to slip-on Pipe Flanges, which are used with Pipes with external threads.

  • Blind Flange Flange

Blind flanges are used to blank off  the end of pipes, valves and opening of pressure vessels since they are built without boring. . In terms of internal pressure and bolt loading, blind flanges, particularly those in larger sizes, are the most highly stressed Flange types.

  • Lap Joint Flange

A lap-joint Flange is a two-part assembly that contains of a stub end with a lap-joint ring Flange positioned over it. After butt welding the stub end to the Pipe, the Flange ring can be rotated to align with the mating Flange. This Flange connection is generally useful for large or difficult-to-adjust Flanges.

  • Weld Neck Flanges

Welding Neck Flanges can be detected by there long tapered hub that gradually extends over the wall thickness of a pipe or fitting. Weld Neck Flanges are primarily used to lessen the curve from a larger size of Pipe to a small size, resulting in higher pressure than before of the run.

  • Reducing Flange

Reducing flanges are used to connect large and small pipe sizes without the use of a reducer. These flanges are available in all pressure classes and are ideal for connecting two different sizes of pipe. If an abrupt transition, such as at a pump, would cause unwanted turbulence, this type of Flange should not be used.