Types of flange connection

Flange connection is a kind of detachable joint that first fix two pipes, pipe fittings or equipment on one flange, then add flange gasket between the two flanges, and finally tighten the two flanges with bolts to make them closely combined. It can realize the connection between the static pipeline and the rotating or reciprocating equipment. Flange connection can be divided into five types: flat welding, butt welding, socket welding, loose sleeve and thread. The first four are described in detail as follows:

Weld neck flanges WN flanges A182 Gr F347 RTJ ASME B16.5

Weld neck flanges WN flanges A182 Gr F347 RTJ ASME B16.5

Flat welding: only the outer layer needs to be welded, but the inner layer does not need to be welded; it is commonly used in medium and low pressure pipelines, and the nominal pressure of the pipeline should be less than 0.25MPa. There are three kinds of sealing surface of flat welding flange, which are smooth type, concave convex type and tenon groove type. Among them, smooth type is the most widely used, and the price is affordable and cost-effective.

Butt welding: the inner and outer layers of the flange should be welded, which is generally used in medium and high pressure pipelines, with the nominal pressure of 0.25 ~ 2.5MPa. The sealing surface of butt welding flange connection is concave convex type, and the installation is relatively complex, so the labor cost, installation method and auxiliary material cost are relatively high.

Socket welding: generally used in pipes with nominal pressure less than or equal to 10.0MPa and nominal diameter less than or equal to 40mm.

Loose sleeve: it is generally used in the pipeline with low pressure but corrosive medium, so this kind of flange has strong corrosion resistance and is mainly made of stainless steel.

This kind of connection is mainly used for the connection of cast iron pipe, rubber lined pipe, non-ferrous metal pipe and flange valve, and the connection of process equipment and flange also adopts flange connection.

Hebei Haihao Group is one of the leading manufacturer of pipe fittings and flanges in China. We have all kinds of flanges with all kinds of materials.Email:sales@haihaogroup.com