Pipes are the veins of every base. They carry breathing air into the rooms, exhaust outside and coolant to the radiators. Once you understand how the game treats a pipe network, you build less and repair less often.
One network, one content
All pipes directly connected to each other form a network. The game treats this network like a single container: pressure, temperature and mixture are the same everywhere in it. So it does not matter where you measure or feed in.
Networks are only separated by devices: pumps, regulators, valves, filtration units and the like. Each of these devices has ports on two or more networks.
The volume of a network is the sum of its parts:
| Part | Volume |
|---|---|
| Pipe (Straight) (per piece) | 10 L |
| Liquid Pipe (Straight) (per piece) | 20 L |
| Passive Vent | 100 L |
| In-line tanks small / medium / 1×3 | 100 / 250 / 360 L |
| small / large tank (in-line) | 6,000 / 50,000 L |
A calculation: 30 gas pipes and one passive vent give 300 + 100 = 400 litres. At 1,000 kPa and 20 °C they hold n = 1,000 · 400 / (8.3144 · 293.15) ≈ 164 mol.
Which line for what
| Line | Content | Maximum pressure | Heat exchange |
|---|---|---|---|
| Pipe (Straight) | gas | 60,795 kPa | yes |
| Insulated Pipe (Straight) | gas | 60,795 kPa | no |
| Liquid Pipe (Straight) | liquid | 6,079.5 kPa | yes |
| Insulated Liquid Pipe (Straight) | liquid | 6,079.5 kPa | no |
Gas and liquid pipes do not connect to each other. Only devices with both kinds of port make the transition, such as the purge valve or the electrolyzer.
The Kit (Pipe) builds every shape: straight, corner, T piece, crossings with three to six branches and long straight pieces. A T piece or crossing costs two to three kits. Long pieces save, on the other hand: the pipe with ten lengths (100 L) costs 8 kits instead of 10, the one with five lengths 4 instead of 5.
Limits and damage
- A gas network holds at most 60,795 kPa and counts as stressed from 80 % – about 48,636 kPa.
- More than 2 % liquid in a gas pipe damages it. That happens sooner than you might think: pollutant turns liquid from just 1,800 kPa at room temperature, carbon dioxide from 517 kPa below 266 K – for example in an outdoor line during a Mars night.
- Liquid pipes only hold 6,079.5 kPa, a tenth.
- If liquid falls below its freezing point, it solidifies in the pipe into chunks of ice that end up in the world. Water freezes at 273.15 K.
With the same amount, pressure rises in the same ratio as the temperature in kelvin. A network at 40,000 kPa at 20 °C already sits at about 50,900 kPa at 100 °C – above the stress limit.
Liquid lines are different
In a liquid line, liquid and gas share the volume. As pressure, the game at first only shows the pressure of the gas in the remaining volume. Only when the liquid fills more than the network volume minus 0.1 litres is liquid pressure added: 10 / (1 − fill level) − 10 kPa. In a 200-litre network it then jumps all at once to about 20,000 kPa – the pipe bursts.
So pressure is no good as a fill gauge. Measure the fill level instead: VolumeOfLiquid divided by Volume, both supplied by the Liquid Pipe Analyzer. This program keeps a line between 80 and 90 % fill and also has an emergency stop based on pressure:
# Fill a liquid line by fill level
define PUMP -454028979 # Liquid Volume Pump (StructureLiquidVolumePump)
define ANALYZER -2113838091 # Liquid Pipe Analyzer
define NPUMP HASH("Water Pump")
define NANALYZER HASH("Water Analyzer")
define FULL 0.9 # fill level, stop from here
define REFILL 0.8 # fill level, restart from here
define PMAX 5000 # kPa, emergency stop below 6,079.5 kPa
alias volume r0
alias liquid r1
alias level r2
alias run r3
alias pressure r4
alias tmp r5
start:
yield
lbn volume ANALYZER NANALYZER Volume 0
bnan volume start # no analyzer with this name
lbn liquid ANALYZER NANALYZER VolumeOfLiquid 0
lbn pressure ANALYZER NANALYZER Pressure 0
div level liquid volume # fill level 0 to 1
slt tmp level REFILL
select run tmp 1 run
sgt tmp level FULL
select run tmp 0 run
sgt tmp pressure PMAX
select run tmp 0 run # emergency stop on high pressure
sbn PUMP NPUMP On run
j startThe analyzer sits on the network the pump fills – behind its output. How lbn works with names is explained in IC10: control a device by name.
Insulate or not
Normal pipes exchange heat with their surroundings – through the air, by radiation and in the sun. A straight piece only has small values (convection 0.005), but over long lines it adds up. Insulated pipes exchange no heat at all.
- Insulate: cooling loops inside the base, hot exhaust, outdoor lines whose content should keep its temperature.
- Do not insulate: lines to radiators and every stretch where heat is meant to go out or in.
More in Heat exchangers and heat transport: pipe to pipe, gas to liquid.
When gas disappears
A network only loses gas where it is connected to something else. Work in this order:
- Measure: read
TotalMoleswith a Pipe Analyzer over a few minutes. If the value drops although no consumer is running, gas is leaving. If only the pressure drops but not the amount, the network has merely cooled. - Check vents: a Passive Vent equalises with its room every tick – even if it hangs outside.
- Check valves and regulators: an open digital valve joins two networks, which then rise and fall together.
- Look for damage: watch for pipes that were above the stress limit or held liquid.
Where next
- Pumps, valves and pressure regulators: which part for what – which device belongs between two networks
- Tanks and gas storage: sizes, insulation, safe filling – stores as part of the network
- Evaporating, condensing, freezing: using phases on purpose – when gases turn liquid in pipes
- Basics of pressure: Atmosphere and pressure, calculator: Gas calculator