Solution to the pipeline upturning problem
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There’s one thing I’ve never quite understood: why do the branch pipes that extend from the main pipe on the pipe rack always first bend upward before turning sideways? The experienced workers say that unless there is no pressure involved or it’s required by the manufacturing process, it’s not advisable to bend the pipes downward before extending them; bending them directly to the side is also not ideal. I still don’t understand why=-=
The vapor pipelines in the pipe gallery generally run upward; for some exhaust gases, Y-shaped tees are used. The liquid pipelines can run downward, though there are also cases where they run upward. These are all my personal opinions; please feel free to share your thoughts
If the branch pipe is bent directly from the side, its own weight combined with the weight of the fluid inside it can cause the branch pipe to bend. This deformation is particularly noticeable when the temperature of the fluid inside is high, and it can lead to stress cracking in the welds that connect the branch pipe to the main pipe, resulting in leaks. The branch pipe extending from the main pipe first bends upward and then to the side; this may cause bending or deformation of the branch pipe, but it has little impact on the weld connecting the branch pipe to the main pipe, thereby extending its service life.
Branches of steam pipelines or gas pipelines must be led upward to ensure that no liquid enters the fluid flowing in those branches, thus maintaining the quality of the fluid. For liquid pipelines, they can be directed upward or downward, depending on the piping layout. Leading branches out to the sides too much can, first, affect other pipelines mounted on the pipe rack, and second, cause high stress, which is not appropriate.
The one on the 3rd floor makes sense, but the main consideration is collision. Pipes will always need to be added to the pipe gallery in the future.
This is an example from pipeline design specifications; it is intended to reduce the impact of fluids on the stresses in the pipelines as well as the resistance to fluid flow within them. The effect of stresses is the main factor to be considered! !
When moving upward or downward, the properties of the process medium must be taken into consideration first; for example, steam can only be introduced from above, condensate and flare lines must be connected to the main pipeline from above, and pipes containing solid particles can only be introduced from below； On the other hand, the elevations of pipes in different directions on the pipe tray should be staggered to avoid collisions.
In my opinion, it is necessary to consider three main aspects: first, reducing stress; second, reducing the impact force of the medium; and third, preventing the entry of impurities
What was said on the third and eighth floors is great; I’d also add that the piping layout should be aesthetically pleasing and well-organized； The calculation of stress also needs to be taken into account.
Walking this way makes it harder for rust and other dirt to get in, and it also facilitates the release of gases
I have also seen a situation where, for an exhaust gas vent line leading to a flare, why is it necessary to use a Y-shaped elbow? Please have the knowledgeable friend explain it; thanks in advance!
The gas branch pipeline, following the flow direction, connects to a Y-shaped tee, resulting in less resistance compared to when it connects to a vertical tee on the main pipeline
Why can pipes containing solid particles only be connected from below? The particles settle at the bottom of the main pipe; if something is led out from below, won’t the branch pipes then be filled with particles?