Almost everything in Stationeers revolves around gas: air to breathe, fuel, coolant. Once you understand how the game links pressure, amount and temperature, you can work out in advance whether a tank is big enough or a wall will hold.
Pressure, amount and temperature
The game uses the ideal gas law: p · V = n · R · T, with R = 8.3144 J/(mol·K) – IC10 has the constant rgas for it.
An example with numbers: one large grid cell is 2 × 2 × 2 m, i.e. 8 m³ or 8,000 litres. How much gas does normal pressure at 20 °C take?
- n = p · V / (R · T) = 101.325 kPa · 8,000 L / (8.3144 · 293.15 K) ≈ 333 mol
So a room of 4 such cells needs about 1,330 mol. That helps with planning: a small tank holds 6,000 litres. Filled to 5,000 kPa at 20 °C that is a good 12,300 mol – enough for more than 35 of those cells. The tank is part of the pipe network and has no logic of its own; you read its pressure with a Pipe Analyzer on the same network.
When an enclosed gas warms up, its pressure rises in the same ratio as its temperature in kelvin. A room at 100 kPa and 20 °C (293 K) is already at 110 kPa at 50 °C (323 K).
Mixtures and partial pressure
In a mixture every gas contributes its share of the pressure. The partial pressure of a gas is its fraction times the total pressure. Your lungs only care about the oxygen partial pressure (full efficiency from 16 kPa); toxic gases give a warning from 0.5 kPa and damage from 1 kPa. More in Survival: the first minutes.
What walls and pipes can take
Every part withstands a certain pressure difference between its two sides. It is the difference that counts, not the absolute pressure:
| Part | holds pressure difference |
|---|---|
| Iron Wall (Type 1) | 200 kPa |
| Composite Wall (Type 1) | 300 kPa |
| Airlock | 1,000 kPa |
| Reinforced Window (Composite) | 8,000 kPa |
| Reinforced Wall | 10,000 kPa |
Pipes have fixed maximums from the game code:
| Line | Maximum pressure |
|---|---|
| Gas pipe | 60,795 kPa |
| Liquid pipe | 6,079.5 kPa |
| Duct | 1,215.9 kPa |
A gas pipe network is already under stress from about 48,600 kPa. And liquid does not belong in a gas pipe: more than 2 % liquid damages it.
On hot worlds the pressure in tanks and pipes rises with temperature. Keep a clear margin to the limits there.
Getting gas in and out
- Passive Vent equalises pipe and surroundings instantly – no power, no control.
- Active Vent runs on 100 W in two modes: Outward blows gas from the pipe into the room, Inward sucks it out. It moves at most 10 kPa per tick. You set the limit pressures with
PressureExternal(room) andPressureInternal(pipe); every write toModeresets both to their factory values. - Volume Pump pushes gas from one pipe network into another – even against the pressure. More in The volume pump in depth.
Measure instead of guessing
The Gas Sensor measures the air where it sits: pressure, temperature, total moles and the fraction of every gas. For pipe networks there is the Pipe Analyzer (yes, the game really spells it that way). Both are the basis for any IC10 control – see IC10: control a device by name.
When gases turn liquid
In Stationeers every substance has a freezing point, a lowest pressure from which it can be liquid, and a critical point above which there is no liquid at all. In between lies the vapour pressure curve.
An important example is carbon dioxide: it only turns liquid from 517 kPa and only below about 266 K (−7 °C). At normal pressure it goes straight from gas to ice.
You will find the phase diagrams of all substances under Gases.
Fire
For gas to burn it needs fuel and an oxidiser – at least 0.00001 mol of each – plus ignition. Fuels are methane (Volatiles), hydrogen and alcohol; oxidisers are oxygen, nitrous oxide and ozone. Pumping in carbon dioxide or nitrogen does not put out a fire on its own. What the reactions produce:
In short
- Amount in mol = pressure × volume ÷ (8.3144 × temperature in K).
- Walls hold pressure differences – iron wall 200 kPa, composite wall 300 kPa.
- Gas pipes up to 60,795 kPa, liquid pipes up to 6,079.5 kPa.
- CO2 only turns liquid from 517 kPa.