This makes absolutely zero sense to me...

[Frustrated]

Spoiler

That is a sealed chamber that was pumped clean to a vacuum by that very same pump.  How do those pockets of non-Natural Gas get in?

[speckle21]

1.  You fed in the gasses accidentally

2. When you pumped it to vacuum it wasnt a total vacuum. there may have been a lingering microbubble of gas you didn't notice.

3. If you have gas liquification system somewhere below the chamber then the gas may have teleported into the chamber by the liquid transport bug.

4, There seems to be debris in the chamber, maybe there is a solidified hunk of gas hidden in the debris?
 

But i'm betting on 1. You fed the gases accidentally. Your system might not be as fool proof as you thought. Try putting a filter before feeding the natural gas to ensure its pure. 

[Fleetfeet]

I would guess the same way the natural gas got in. Without more context it's basically impossible to say.

...but yeah, my guess would be the contaminants were still in the nat gas chamber you were pumping from, or whatever you've got filtering natural gas is/was imperfect, if you're using physical filters.

On the bright side, if this is set up as infinite storage it wouldn't be too hard to fix, if you even cared to fix it. It isn't going to do any harm outside of damaging a generator a little when you run out of natural gas. It might do some ego damage otherwise, but it's pretty harmless considering they're all lighter gasses.

Edited May 15 by Fleetfeet

[Frustrated]

That sealed room is fed by a petroleum refinery, which is sealed behind a liquid lock (crude oil liquid).  I made sure to pump both rooms clean.  I don't have the means to solidify gases and have no idea how to do it.  I'm not sure how to do infinite storage, actually.

[Bzhydack]

18 hours ago, Frustrated said:

That sealed room is fed by a petroleum refinery, which is sealed behind a liquid lock (crude oil liquid).  I made sure to pump both rooms clean.  I don't have the means to solidify gases and have no idea how to do it.  I'm not sure how to do infinite storage, actually.

Both O2 and PO2 can be effect of sublimation. Maybe in pile of debris you have PDirt/Slime and Oxylite.

But Hydrogen most likely was just feeded accidentaly.

BTW, you dont need room this large for infinite storage, but upside is you can ignore patches of wrong gases as long as they have lower density 😉

[Fleetfeet]

On 5/15/2026 at 8:29 AM, Frustrated said:

That sealed room is fed by a petroleum refinery, which is sealed behind a liquid lock (crude oil liquid).  I made sure to pump both rooms clean.  I don't have the means to solidify gases and have no idea how to do it.  I'm not sure how to do infinite storage, actually.

Curious. If not part of infinite storage, what's with the liquid at the bottom of the room?

[Frustrated]

I have no idea.  Weird things tend to happen in my colony.  I get a lot of random liquid shifts, like a large amount of crude suddenly shifted to the other side of a granite wall into a salt water lake, for example.