The collision mask is incorrect. They are placeable on land like the regular ones but not on water.

You can do it! ;-)

.-.

damm

Fixed B)

i do have the last update and still have this problem

still placeable in land? last time i got it working... i may check it later, meanwhile could you try making a test save? only using the mod, to see if there is another one modifying something.

you are right, the test save works, so some other mod is be the culprit.
I suspect it's SE since it touches a lot vanilla stuff, i'm playing ATOM + additional mods for reference.
the ingame info box says: under water pipes > space exploration > all the overhauls modpack
What parameter should i modify to make it buildable on water and not on land?

well, because of SE and the modpack, the problem is internally: one of them is modifying the pipes.

I'm the one looking down here, since its directly related to the load order. I'll log the pipe's data and check what changes are being made, then i'll make the patch and should work again.

ATOM only touches the recipes and the technology.

indeed, it was one of it dependencies, it seems its "5Dim New Compatibility", since there is a script that, arbitrarily, hard-codes all the pipes to have the same collision masks.

I'll try making a little trick, i'll create a second script that, once detected this other mod, it will force set all my pipes back to their collision masks.

done. may you try version 1.2.3?

the fix is applied when "5Dim's New Compatibility" and "Krastorio2" are both enabled (5Dim only touches the pipes when Krastorio2 is also enabled).

I tested 1.2.5 ant it works, thanks for the fix!

B)