General knowledge of forged flanges

For those who don’t know much about flanges, flanges are actually a common disc-shaped part that helps connect pipes, equipment, etc.Forged flange because of its excellent joint performance, in many places has been rapidly promoted and applied.But many people still have a lot of questions about them.So today, we’ll answer some common questions one by one.

API 6A Weld Neck Flanges

What is the connection method for flanges?

In pipeline construction, flange connection is very important, it is two pipes, pipe fitting or equipment first fixed on a flange, and then add a flange gasket between the two flanges, with bolts to connect them together.Some flanged fittings and equipment connections are also flanged.

Flanges are divided into threaded flanges and welded flanges.Threaded flanges are used for low pressure and small diameter cases, while welded flanges are used for high pressure and large diameter cases.Flange thickness at different pressures and the diameter and number of connecting bolts are different.Flange gaskets also vary from low pressure or high pressure asbestos gaskets to metal gaskets, depending on the pressure class.Flange connection, easy to operate, can withstand greater pressure. Flanged joints are widely used in industrial piping.

ANSI B16.5 A105 RF forged slip on flanges

What’s the use of flanges?

Flanges are used to connect pipes, valves and other equipment.The flange may also be a plate or ring, when fastened to the pipe, forms a rim at the end of the pipe.A blind flange, for example, is a plate that covers or closes the end of a pipe.Flange connection is a kind of connection between pipes, connectors have flanges, through the flanges will be bolted together parts.

What are the main principles in selecting flanges?

Slide on flanges are designed for pipes with a temperature of 300℃ and a nominal pressure of less than or equal to 2.5 MPa.The weld neck flange is designed for pipes with a temperature greater than 300℃ or a nominal pressure greater than or equal to 4.0 MPa.Therefore, when selecting a flange, you must consider the use environment of the flange (such as pressure and temperature),choose the appropriate material.

In order to ensure that the installed flange does not leak, what factors should be paid attention to during the installation process?

First of all, the flange should be strong enough that it should not be deformed when tightened.Flange sealing surface should be clean, installation should be careful to remove oil and rust.Second, gaskets should have good oil resistance and aging resistance, as well as good elasticity and mechanical strength.The cross section and size of the gasket shall be determined according to the shape of the joint, and the gasket shall be placed correctly.Third, the tightening force of flange should be uniform, and the compression control of rubber gasket should be about 1/3.In addition, the maintenance of the flange is also very important to prevent damage caused by leakage.