Fluids and pipes: water, lava, oil and temperature routing
The short version: fluids in FluxWerks are simulated, not animated — they flow, pool, press against what you build, and react where they meet, so the rule that saves you is to pump it, pipe it, and route it by temperature. Water, lava and oil all behave differently, and lava is the one that will fill in your own cooling channel if you let it.
What the official feature list states
The developer's page has a section called "Fluids with real flow", and it makes four concrete claims:
- Water, lava, oil and stranger substances flow, pool, and press against your works.
- Fluids react where they meet.
- Lava hardens into rock in your cooling channels.
- Hot springs can power an early base.
The instruction attached to all of it: pump it, pipe it, and route it by temperature.
Why temperature routing beats distance routing
In a game where fluids are simulated, a pipe run is a thermal decision. The shortest route may carry fluid past heat sources or through a biome that changes what happens to it on the way. Because fluids react where they meet, an oil line and a water line that cross carelessly is a problem you built yourself.
| Routing habit | What the simulation does with it |
|---|---|
| Shortest pipe, ignoring temperature | Fluid arrives having gained or lost heat somewhere you did not plan |
| Lava through a cooling channel | The lava hardens into rock and blocks the channel |
| Water routed past furnaces | It boils away — the store page states water boils under heat |
| Hot spring tapped early | It can power an early base, if the route respects its temperature |
| Two reactive fluids meeting at a junction | They react where they meet, wherever that junction happens to be |
Pumps, pipes and the terrain you carve for them
Terrain and fluids are one system: the official feature list says you can dig shafts to deep ore veins, carve canals for your cooling water, flatten mountains, or tunnel your logistics straight through rock. Carving a canal for cooling water is explicitly one of the intended terrain moves, not an exploit.
Practical consequences for a first base:
- Water needs a path you control. Carve the canal rather than hoping terrain cooperates.
- Lava needs containment, because it hardens where your cooling is — either route it far from channels or accept that a leak becomes permanent rock.
- Oil is a separate line. It is listed as its own fluid with its own behaviour, so keep reactive pairs apart until you have a junction you chose.
Diagnose a line that stops moving
Use Flow View to inspect connections before rebuilding a long run. For buffering and distant delivery, continue with Logistics & Drones. For fluid temperature and generation, use Heat & Steam.
What v0.5.15 changed for pumps and pipes
Official Steam notes for v0.5.15 (September 24, 2026) reworked how pumps and pipes report flow. This is the first post-launch fluids patch.
| Change | What it does |
|---|---|
| Pipe Flow | Select a pipe to see what fills it, what empties it, and which side is the bottleneck |
| Pump / router / output tick | All three now move fluid ten times a second; a short pipe between them no longer throttles the line |
| Pipe colours | A pipe that empties and refills keeps its fluid colour; one that stays empty fades to grey instead of flickering |
| Demolish network | Cutting a whole pipe network previews the cut and needs a longer hold on a second button |
The patch before it, v0.5.14 (September 21), already added pipe-to-pipe pumps (a Fluid Pump between two pipes moves fluid from one to the other; same pipe on both sides shows a warning) and a pump temperature filter (limit the pump to fluid above, below, or between temperatures you set).
If a short pipe between two pumps used to feel like a bottleneck, re-test it on v0.5.15 before tearing the line out.
v0.5.16 then put Flow View on pipes as well as belts: lines show fluid moving through the pipe and its buildings, red where something can never work. Belt and pipe tools show it (off under Settings → Construction), as does Overlays or Y. The same patch also fixed flushed pipes not rejoining neighbours and a new pipe between two different fluids joining either one at random — if a join looked cursed on 0.5.15, rebuild it once on 0.5.16 before ripping the network.
Temperature filters and water fixes in v0.5.20
| Symptom | Check or action |
|---|---|
| Filter blocks everything after changing mode | v0.5.20 fixed the Above / Below → Between transition. Update the game, select the intended mode, enter the range and press Apply beside the number box. |
| Fluid Router panel will not open | Selecting a single Router now opens its panel consistently. Select the Router itself before changing its route. |
| Water stops after leaving and returning | The patch fixes water ceasing to flow in an area after flying away and back. Distinguish this from a disconnected pipe or a closed temperature filter. |
| Lake surface stays uneven | The patch fixes lakes never settling and water failing to fill a removed block's space. These were simulation faults, not extra pump requirements. |
| Deep-water extraction appears lower than an old guide | The Deep Vein Extractor now produces 100 water units/min, down from 300, and its panel's incorrect rate was fixed. Recalculate demand with the current value. |
The extractor now needs 1.2 MW and 1.5 MB/s computing; for non-water resources its output is 22.5/min. It wears half as fast and takes Basic Repair Packs. Research access still matters: the scanner hides veins that your research has not opened.
The October previews describe a new pipe-joining system and automatic pumps at building connections for the upcoming 0.6. They do not change how a v0.5.21 installation connects today. Official patch notes.
Next: Heat & Steam · Logistics & Drones · Beginner: First Hour