Resolved [1.1.53] Cannot connect systems with different fluids, when fluids are same

[Kubik]

I added new refinery and want to connect it to the other 2.
Connecting petroleun gas was ok, Light oil told me "Cannot connect systems with different fluids" lets connect it last, because I did not see the issue, heavy old was ok.
I moved the connection point (last placed pipe) few times, to an empty space, removed it and placed it again, but nothing helped.

When writing this I want to get more pictures, because it was not possible to add any pipe back to connect it to other pipe with light oil, but is was possible to extent exiting pipes to an free space, but after replacing many of them (for each checking that it contains only light oil) it started working.

It happen many times, but stop happening, normally when I see this text it is empty pipe, and many pipes connected to it, and somewhere in that some small leftover that is so small it does not even show on most of the pipes (so my mistake), but this time both sides of the pipe was filed with Light oil at same 25°C, so no clue why I get this message, or why it disappeared.

pics

Cannot connect systems with different fluids_1.png (9.03 MiB) Viewed 4076 times

Cannot connect systems with different fluids_4.png (9.21 MiB) Viewed 4076 times

Cannot connect systems with different fluids_3.png (9.69 MiB) Viewed 4076 times

Cannot connect systems with different fluids_2.png (10.28 MiB) Viewed 4076 times

[Loewchen]

If you actually click on the light oil pipes you would see that it contains water, if you follow the pipes you can find a chemical plant producing solid fuel that you connected to your water pipes. NaB.

[Kubik]

oh thank you did not notice that, and I also did not know clicking on the pipe will show any information, including this in tutorial might be an useful for someone else who does not know this yet.
But also it is questionable if the water was actually in the system, because after you hint how it happen I reproduced it, but the water was not connected to the pipe, it was just next to "unused" input of the chemical plat, but was not entering the chemical plant, so there is some room for improving both the error message, and the actual handling of situation when someone change product of an chemical plant.

[Kubik]

As shown here the left pipe is empty and at same time claim to contain18k of water.
Until now I assumed that the two inputs are independent. But now it seems inconsistent, they are connected, but water does not go trough

pics

water does not go trough the chemical plant.jpg (1.88 MiB) Viewed 4044 times

[Silari]

Inputs will only input fluid, they can not output fluids so the water can't pass through (even if the input accepted water, which they don't). They inputs connect to the same fluidbox, so the game considers anything that touches either input as part of the same fluid system - it doesn't care how fluid can flow, only that they are connected somewhere. Fluid counts are for the entire system, so even if an individual pipe/section of pipes is empty it can be part of a system that contains fluids. I doubt they want to go down another rabbit hole of trying to account for edge cases in fluid systems again - the last time didn't end well, and is why we have the pared down anti-mixing system we have now.

Here's an example I setup a while ago to explain it. Notice how the left pipe is considered the same system as the water pipe on the other chem plant, due to it touching an input while the other input touches the other chem plants input with the water pipe touching the other water input.

[Tertius]

This message can also pop up if you add a pipe (intended for one fluid) directly next to an existing pipe that is connected to a fluid system for a different fluid. You assume both will not connect, but actually the game tries to connect each pipe that is next to other pipes with each other.

See this example:

Screenshot 2022-02-07 190706.png (113.13 KiB) Viewed 4006 times

You want to create 2 parallel pipes to the right, but the game doesn't allow this, because it automagically connects each pipe element that is next to each other. It tries to connect the red pipe to what is next to it, and to the bottom there is the petroleum gas pipe - but that's forbidden, so the game refused this.
If you want parallel pipes, you need to use underground pipes like this:

Screenshot 2022-02-07 191051.png (148.32 KiB) Viewed 4006 times

Underground pipes will not connect to every side, only to where the opening is, so this will work.

[Kubik]

@Tertius your example is expected behavior, coding it in a way to allow parallel pipes would be crazy complicated. (Probably easiest would be to give player straight not connecting pipe, right angle pipe, and T pipe, and let player to design it)
But my issue was that is was not really connected (my point of view) to any other liquid.
And claim it was coded this way looks more like an oversight, than a weird design decision.