Large tube with small tube structure
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In the pipeline design for our factory, there are several small pipes that need to cross a road (with a diameter of 89 mm). I was thinking of using a large pipe with a diameter of 2 meters, welding gussets to this large pipe and then installing supports, thereby creating a structure in which the large pipe surrounds the smaller pipes. I would appreciate everyone’s opinions on this – is this allowed according to the relevant standards?
The specifications do not cover this aspect, but I have seen piping of this type
It seems to be mentioned in the pipe rack table; it’s possible. It is also widely used in practice; for example, in fixed-bed gas generation, large-diameter pipes often employ this method. The more you do it, the more standardized it becomes.
There is no explicit specification regarding large pipes behind small pipes, but this practice is used in actual piping work and in pipe rack drawings. As for the pipes with a diameter of 2000 mm, several DN80 pipes are placed behind them; it is necessary to arrange the pipe supports as closely as possible, and also to take into account the wall thickness of the supporting pipes (gaskets should be used if necessary). Also, please take into consideration the medium in the pipeline (whether it is an oxygen pipeline or a pipeline for flammable and explosive substances).
Why not? However, during design, the small tubes must be equipped with supports in accordance with the specifications. If welding is not allowed on the large pipe, use a hoop and then weld on the hoop. This post was last edited by ddfmy on 2009-2-15 14:24]
Allowed; Section 8.4.7 of the Power Piping Design Manual specifies the design parameters for large pipes surrounding smaller pipes