What are the classification of flanges?
Flange type or structure type is mainly divided according to the way of connecting flange and pipe, which can be divided into integral flange, necked threaded flange, butt-welding flange, necked flat welding flange, necked socket welding flange, plate flat welding flange, A-type butt-welding ring plate loose-set flange, B-type butt-welding ring plate loose-set flange, plain welding ring plate loose-set flange, pipe-end flanging plate loose-set flanges (A-type), flanging short-section plate loose-set Flanges (B type) and flange cover (also called blind flange) and so on.
Integral flanges are mainly for pumps, valves, and other mechanical equipment, inlet and outlet flanges, are specifically used for flange connection with the pipe. These inlet and outlet flanges are usually made into a whole with the shell of the mechanical equipment as part of the equipment. The flange is usually molded with the equipment shell casting, and a few casting molding (such as forged steel valves on the end of the flange).
What are the 3 most common flange types?
The threaded flange at the flange bore is processed into pipe threads, and with the threaded pipe with the realization of the connection, is a non-welded flange. Compared with the welding flange, the threaded flange has the characteristics of easy installation and maintenance and can be used in some pipelines where welding is not allowed on-site. Alloy steel flange has enough strength, but is not easy to weld, or welding performance is not good, can also choose a threaded flange. However, it is not recommended to use threaded flanges to avoid leakage when the temperature of the pipeline changes drastically or when the temperature is higher than 260℃ or lower than -45℃.
Butt-welding flange is also called high neck flange, which is different from other flanges in that there is a long and inclined high neck from the welding place of the flange and pipe to the flange disk, and the wall thickness of this high neck gradually transitions to the thickness of the pipe wall along the height direction, which improves the discontinuity of the stress, and thus increases the strength of the flange. Butt-welding flanges are mainly used in harsh working conditions. Such as pipeline thermal expansion or other loads and making the flange at the stress is large or stress changes repeatedly occasions; pressure, temperature fluctuations in the pipeline or high temperature, high pressure, and low-temperature conditions under the application of the pipeline.
Flat-welding titanium flanges are also known as lap-welding flanges. The flat welding flange is connected with the pipe by inserting the pipe into the flange bore to the appropriate position first, and then welded, the advantage of which is that it is easier to be centered during welding assembly and cheaper, and thus has been widely used.
