joining of fluids

[Grifonice99]

I was starting to build the plant for the production of sulfuric acid and I'm going to notice that factorio made me combine the fluids which, if I'm not mistaken, could not be done

factorio bug.png (407.05 KiB) Viewed 1496 times

[Loewchen]

The game did not make you do anything, you connected different fluid boxes, don't do that.

[Squelch]

The game did not make you do anything, you connected different fluid boxes, don't do that.

"Don't do that" would be fine if it wasn't so easy to make the mistake.

This has been encountered a few times, and while it is not possible to incorrectly connect pipes to machines that have a recipe set, it is very possible to place the pipes first, and then add, or change the recipe in the machine. This is done silently, and in some cases (modded games where there are multiple same inputs that are repurposed with different recipes) the cause of fluid contamination is not apparent, or even intuitive (inputs do leak out)

See:
Direct example
Multiple fluid in one pipe system?
Other discussion
[1.0.0] Fluid does not show in pipe window

I do agree that this would be considered an edge case, but I disagree that it is working completely as intended - especially the inputs leaking out and silent bad connection.

[Edit to Add]
The behaviour previous to the last fluid box changes prevented bad connections when setting the recipe with a sound, and the action being rejected. This was also true for rotating machines that would result in a bad connection. While annoying, it did at least allow the player to revise the pipe layout beforehand. If possible, this old behaviour would be preferable in my opinion.

[Loewchen]

I do agree that this would be considered an edge case

It's not, it is working as intended. Anything beyond manually connecting different fluids is possible and can be fixed by disconnecting and flushing, this is how it is supposed to work and as you have shown yourself, how it works. If you want the game the game to behave differently than intended, make a feature request instead.

[Squelch]

If you want the game the game to behave differently than intended, make a feature request instead.

We crossed posts/edits, and I essentially make the suggestion in the edit. I am not currently aware if this affects any mods other than Pyanodon's, so to make a formal suggestion at this point might seem fruitless. Personally, I'm now aware of the ptifall, and subconsciously avoid it, but I do think that this won't be the last report from others that encounter it.

[sparr]

As far as I know, the built in fluid mixing prevention only reads pipe contents and entity fluid *outputs*, while ignoring inputs. You can't connect both outputs of a refinery or two-output chemical plant, but you can connect both inputs even if they want different fluids.

[Squelch]

As far as I know, the built in fluid mixing prevention only reads pipe contents and entity fluid *outputs*, while ignoring inputs. You can't connect both outputs of a refinery or two-output chemical plant, but you can connect both inputs even if they want different fluids.

That makes perfect sense and aligns with my observations. In the vanilla game this merely prevents the machine from working, and there are no examples of multiple same inputs. Mods, however, can add multiple same inputs and in some cases repurpose them according to recipe. I suspect this use case was not considered during testing. Afterall, everything works as intended in the vanilla game.

The biggest problem with the modded machines is that those extra inputs will then slowly leak their fluid from another connected input into the pipe, so therefore contaminate the whole system. This is unintuitive and really hard to spot later when the contamination causes the factory to cease operation.