IT admin who somehow became the person drawing the SCADA screen, so forgive the basic process questions.
Our compressed air system: two screw compressors, one 2000 L receiver, a refrigerated dryer, then the header to the plant. Both compressors report running/loaded state and discharge pressure through a gateway, the receiver has a pressure transmitter.
I want to draw this in the SCADA designer. Two questions:
- The maintenance lead’s sketch has a check valve after each compressor before they join. Is that needed if only one compressor runs at a time? The other engineer says the compressors “have one inside”.
- In my drawing, when compressor 2 is off, the pipe from it to the receiver still shows flow. How do I get only the running compressor’s line to animate?
I found the receiver and dryer symbols but couldn’t find a compressor in the palette.
If only one runs at a time I’d skip the check valve, less to maintain.
Careful there: when compressor 2 is off, the receiver pressure pushes back into its discharge line. Most screw compressors do have a minimum pressure/check valve built in, but those wear. A separate check valve per compressor is common practice exactly for that.
jessicathompson37 is right on the process side, keep the check valves. I drew a compressor room for a client last year.
Palette: Compressor, Compressed-air receiver and Compressed-air dryer are in the Process library, not the core set, so if you only see some of them, check which libraries your organisation bought. Check valve is in the core set under the Water network family; search the palette for “check valve”.
The animation: a connection has no value of its own. It follows its “from” symbol, so a pipe shows flow while the symbol at its start runs. If your pipe from compressor 2 keeps flowing, it was probably drawn from the receiver towards the compressor, or both pipes start at the same running symbol. Draw them in the flow direction:
Compressor 1 -> Check valve 1 -> Receiver -> Dryer -> header
Compressor 2 -> Check valve 2 ----^and bind each compressor’s Running to its own running value on its Views. Tick Flow arrow on the pipes so the direction is visible. A check valve placed on the line takes the medium of the first connection that touches it. Pipes, cables and connections
Draw the dryer bypass too if you have one, operators always ask why pressure dropped when someone opened it.
Kept the check valves (maintenance lead agreed with jessicathompson37). My compressor 2 pipe was drawn from the receiver, as you guessed. Redrew both from the compressors, now only the running one animates. Compressor symbols appeared after purchasing asked about the Process library, we had only the core set. Bypass added.
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