What is a bag shape?
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When looking at some PID flowcharts, phrases like “try to avoid bag shapes in the piping” or “no bag shapes are allowed” are often mentioned. I don’t understand what this means What is a bag shape? On the pipeline in the flowchart, it is also indicated as: i=1:300. What does this mean? This post was last edited by qq375170364 on 2009-4-21 21:08.]
I=1:300 indicates the slope of the pipe, meaning that the slope value is around 0.003.
The bag shape should either be of the type with a higher upper part, similar to a convex shape, or of the type with a higher lower part, similar to a concave shape. In such cases, it’s best to install an exhaust valve on the upper side in the convex shape, and an exhaust valve on the lower side in the concave shape
Of course, the tube should preferably follow a rising pattern or a falling pattern
i=1/300 – this probably represents the slope, but slopes are usually indicated in pipe layout diagrams; it’s rare to see them indicated in process diagrams. Also, a classmate*, right?
Pouch shape: As the name implies, it resembles a pocket with a bottom edge; if this cannot be avoided, a drain should be added. Special requirements for the piping, such as slope, prohibition of bag-shaped areas, requirement for symmetrical layout (for air cooling), and installation locations of valves or small equipment, must be specified in the PID.
The bag type is of the eccentric different-diameter style; i should represent the taper
If the pipe bulges upward or sags downward, forming a pocket-like shape, it allows other substances and liquids to accumulate inside, thereby affecting transportation. i=1:300 refers to the inclination slope of pipeline installation. During installation, attention should also be paid to which side the slope faces.