I'm having issues when setting up a "closed (infinite) loop gas pipe" in Oxygen Not Included. Does anyone have a set of reliable instructions for building such a system within the game? (to be used for cooling).

Start with a long a long pipe with a pump at the input and a gas vent at the output. Pump a bunch of gas through it, then connect the output pipe to the input pipe and disconnect the pump and the vent. And voila, you have gas which circles infinitely through the pipe without needing to spend any energy pumping it.

Except... not quite. Sometimes you wind up with each gas "packet" getting briefly stuck somewhere, such that every packet is only moving every other tick instead of every tick. Sometimes some of your gas packets decide to stop and turn around - in general, the gas is still flowing in a circle, but there are back ups which slow the whole thing to a crawl.

There are lots of tutorials on how to set up the infinite toilet/water seive loop, but none that I could find on this kind of gas loop. But I've seen it, so I'm pretty sure it can be made to work.

Anyone know how to do this consistently? Or, can anyone confirm that there's a mechanic (e.g. friction inside pipes) that would prevent this perpetual motion machine from working long term?

  • 1
    @Stese this is bad advice. Please do not post this question on Superuser. Rant aside, I would assume the reason it sometimes work is the exact amount of gas in the pipes. I'd try with fuller/emptier pipes and see if it works out better. Jan 10, 2018 at 14:25
  • Also, it might have something to do with bouyancy, see if it works better to have to cold parts below the hot parts. In reality, warmer gas will end up on top of the colder gas, maybe they have coded this into the gas physics. Jan 10, 2018 at 14:32
  • For those confused, Oxygen Not Included has a robust gas and liquid simulation system that the game is built around.
    – DJ Pirtu
    Jan 10, 2018 at 15:00
  • 1
    The amount of gas definitely has an impact, but the exact timing of when you disconnect the pump and/or vent seems to affect it too. Once I get my automation (logic circuits) upgrades up and running I'll play with a few methods that are better controlled / timed and see if I can find something repeatable. P.S. @DJ Pirtu I'm not sure a "robust" simulation is accurate when making a perpetual motion machine is possible ;)
    – Selvek
    Jan 10, 2018 at 15:30
  • 2
    @Stese Imaginary "tone" issues aside, if you're going to take it upon yourself to tell people their question doesn't belong here, you should make sure you actually know what the question is about first. Jan 11, 2018 at 8:23

2 Answers 2


Liquids and gasses in pipes work the same, so the tutorials involving loops apply just the same. In order to have a good loop you need to tell the loop which direction to take via pipe bridges.

I'd suggest deconstructing two sections of the pipe and build a bridge on one side of the section (the part of the bridge to be built onto the section must be the input).

Wait until all gasses move in next to each other and then build the closing pipe from the bridge output onto the rest of the loop.

I suggest you to read into this guide so you can learn more about bridges, pipe priorities and pipe core mechanics here.


You are facing a few different problems.

  1. Direction of the flow. You can add bridges (in-line) to alleviate this and direct the flow. Note: Valves and Shutoffs can also be used in a similar way. But bridges are cheaper and more convenient.

  2. Packages stopping in blocked pipes. A Gas Tank or a Liquid Reservoir can be added as a buffer, preventing the flow from being unable to move. It goes without saying that the reservoir should not be completely full. Also note that the reservoir will work as a direction in the same way as a bridge would.

  3. Packages stopping only every other tick at intersections. This is how intersections in ONI work. If you want to have a continous flow, you will need to make due without intersections. (e.g. bridges as outfeeds/infeeds, but bridges will always have priority over/give priority to the main gas/liquid line)

Side-note: While it would be interesting to see your working solution being posted on the official ONI forum, i have my doubts about it's efficiency. Normally you will have to set up a cooling loop with liquids (more heat capacity) and add an aquatuner to it to cool the medium. Which again needs to be cooled by some other environmental means (e.g. a steam turbine). This is of course very advanced, but i want to prepare you for the underwhelming truth of cooling with gases.;)

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .