Questions regarding the drawing of process flow diagrams
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I would like to ask how to determine the size and position of large equipment in a process flow diagram (I’m a beginner). Thank you all in advance.
In the flowchart, it’s sufficient to show the devices in a schematic form; the dimensions need only be indicated roughly. For processes that rely on gravity-driven flow, it’s important to reflect the height differences between the devices, but overall, it’s enough as long as it looks presentable
In the process flow diagrams, it is not necessary to draw large and small equipment to exact scale; it is sufficient to show their relative sizes. Their heights can be indicated based on the specific layout, and a few devices may not need to be placed at a particular height.
There has to be a standard though; otherwise the devices depicted will look uncoordinated and ugly.
There is no fixed standard; a process flow diagram mainly shows the sequence of operations, while the equipment is represented in a schematic form – as long as the sizes are relatively proportional and it looks good to the viewer, that’s sufficient.
As the previous posters mentioned, when drawing flowcharts, it’s not necessary to follow proportions – they are merely schematic diagrams; of course, it will look better if the proportions of the diagram are appropriate. I usually fold the diagram into four parts before drawing, creating a cross that divides it into four sections; this helps me get an idea of the device’s location and its size relative to the rest of the diagram. For more detail, I can fold it into even more sections.
:funk: LS hand-drawn?
In a process flow diagram, it’s not possible to depict all of the equipment in detail. The flow diagram is meant to show the flow of materials within the process, rather than the equipment itself (although the main inlet and outlet points should be indicated). They are right – it’s just a simple schematic representation; if it ends up looking ugly, that’s your own problem. As long as the overall layout of the diagram is aesthetically pleasing, there’s no requirement regarding the size of the equipment depicted. If you really can’t draw it well, simply scale down the equipment proportionally. Generally, it’s sufficient to simply outline the shape of the equipment. :loveliness: Hehe, I’m here too right now, in Longkou, Yantai
Indeed, there is a significant difference between flowcharts and layout diagrams. Flowcharts do not need to be drawn to scale; it is sufficient to clearly show the flow of materials and the basic functions of the equipment, whereas layout diagrams must display coordinates, elevations, and so on.
In fact, it’s not necessary to draw the inlets and outlets connecting the pipes to the equipment in great detail; it’s sufficient to indicate that there are pipes connected to the equipment.
There are many process flow diagrams on this forum; refer to these for learning, and also study carefully the contents and uniformity requirements specified in HG 20519-92(T)_Code for Chemical Process Design and Construction Drawings (which is also available on this forum).
In a process flow diagram, the equipment is not required to be drawn to scale; it is sufficient to indicate the heights of the key inlet and outlet positions. The exact size at which it should be drawn depends on the size of the diagram and the number of other devices, and this decision should be made by the designer. There is no need to draw smaller devices extremely small – it is enough for them to be clearly recognizable as equipment in the diagram. The placement of devices in a flowchart requires some attention to detail; when arranged properly, there are fewer conflicts between the various material flows within the flowchart, and it appears more aesthetically pleasing.