What does “no bag shape” mean?
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On the PID diagram, what does it mean when some pipelines are marked as “no bag”?
This post was last edited by ylb913 on 2016-1-17 at 12:32; it means that liquid is not allowed to remain inside the pipeline, and the formation of a U-shaped tube is not permitted. This is mainly used for the transportation of low-pressure gases, or gases whose condensates are corrosive. The main hazards associated with U-shaped tubes are, first, liquid sealing, and second, corrosion. For such piping, it is generally required that the slope be downward at each step, or upward at each step, or higher in the middle and lower at the ends; sometimes the piping also needs to have a certain slope so that the liquid can flow smoothly into the equipment at one end or at both ends.
No matter where the pipeline is installed, it will not form a pocket shape that could hold liquid.
The answer on the 2nd floor was very detailed; I learned a thing or two from it
The answer on the 2nd floor is very detailed; I’ve learned from it
The inverted U shape is another case, namely the so-called “air bag””； The U-shaped part is the liquid bag.
The beltless type means that the entire tube has a constant rise or fall in level; there are no U-shaped liquid pockets nor inverted U-shaped air pockets, which are collectively referred to as pocket types
The answer on the 2nd floor was good; thank you, I’m learning*
Thank you everyone. It’s been very helpful