Satisfactory Pipes: Head Lift, Sloshing and Real Throughput

Pipes behave less predictably than belts, and almost every complaint about them comes down to one of two things people were not told: fluids fight gravity, and the flow rate you see fluctuating is usually correct behaviour rather than a fault.

The two marks

Mark	Throughput	Unlocked at	Cost per segment
Pipeline Mk.1	300 m³/min	Tier 3 — Coal Power	1 Copper Sheet
Pipeline Mk.2	600 m³/min	Tier 6 — Pipeline Engineering Mk.2	2 Copper Sheet, 1 Plastic

Both come in a Clean variant with the same throughput and no external flow indicator, for when you care about how the factory looks.

Pipe segments run 1 to 56 metres, the same range as belts, and hold 1.327 m³ per metre of internal volume. That last figure matters more than it looks: a long pipe is also a buffer, and a long pipe takes a while to fill before anything comes out the far end.

Head lift is the thing nobody explains

Fluids do not climb for free. Moving liquid upward requires head lift, and without enough of it the flow simply stops partway up.

Two numbers to hold onto:

• A perfectly horizontal pipe still needs about 1.3 m of head lift to fill, because of the pipe’s internal geometry. Level is not free either.
• Pipeline Pump Mk.1 provides 20 m of head lift and draws 4 MW. Mk.2 provides 50 m and draws 8 MW.

The rule that catches people: head lift does not stack. Putting two pumps next to each other does not give you 40 m. Space them out along the climb so each one takes over where the previous one’s lift runs out.

Gases behave differently — they are not subject to head lift the way liquids are, so a nitrogen line up a cliff is a very different proposition from a water line.

Sloshing: the flow rate that will not sit still

Watch a Mk.2 pipe indicator on a busy line and you will see it dip below 600 m³/min periodically. This is sloshing, it is by design, and it is not a bug.

Fluid can flow backwards briefly in a pipe, which interrupts flow and drops the instantaneous rate. The wiki is explicit that this is intended behaviour. The practical consequences:

• Do not plan for exactly 600 m³/min on a Mk.2 line. Leave headroom, or accept occasional dips at the consumer.
• Buffers smooth it out. A Fluid Buffer between producer and consumer absorbs the fluctuation and delivers steadily.
• Junctions make it worse. Every branch is another place fluid can slosh back. Fewer, longer runs behave better than a web of splits.

Fluid Buffers

Building	Capacity	Unlocked at
Fluid Buffer	400 m³	Tier 3 — Coal Power
Industrial Fluid Buffer	2400 m³	Tier 5 — Petroleum Power

Six times the capacity for the industrial version. Similar-sized buffers can be stacked on each other, which is how people build tank farms in a small footprint.

Buffers do three useful things: absorb sloshing, cover a producer that runs in bursts, and give you somewhere for surplus to go instead of backing up the line. On any refinery setup with variable input, a buffer between stages is worth its cost.

Flushing

Pipes retain fluid, and that becomes a problem when you want to change what runs through a line, or when a line has deadlocked with an air pocket.

You can flush a single pipe or the entire connected network from the flush option. Full network flush is the tool to reach for when a system that used to work has stopped moving and you cannot see why — a trapped pocket at a high point is a common cause.

Overflow valves and controlling direction

The Overflow Valve passes fluid only when pressure builds behind it, which makes it the fluid equivalent of a Smart Splitter set to Overflow. The standard use is dumping surplus to a sink or a buffer so a full downstream tank does not stall the whole refinery.

When to stop using pipes

There is a point where the pump count stops being worth it. Two alternatives:

Trains with fluid freight platforms. A train does not care about gradient for throughput purposes. It costs power at the stations and delivers in batches rather than continuously, but a 300 m climb costs it nothing in delivered volume.

Fluid Trucks, added in 1.2, with 3200 m³ capacity on both truck and station. Same logic as the train, less infrastructure, lower volume.

A rough decision rule:

• Flat ground, any distance: pipe. Continuous, simple, no batching.
• Moderate climb, short distance: pipe with pumps. Count the pumps first — each is 4 or 8 MW plus the space.
• Large climb, or a climb plus distance: train or fluid truck.
• Gases uphill: pipe. Head lift does not apply the same way.

Colour-coding fluid lines

Once you have more than two fluids running through the same area, identifying a pipe by following it becomes the slow part of every repair. Colouring each line by contents fixes that, and the game’s own colour value for each fluid is available so you are not matching by eye.

One caution from that data: several fluid colours are very dark. Crude Oil in particular is close to black and effectively invisible on dark foundations. Pair the dark ones with a sign or a light rather than relying on the pipe colour alone.

Common mistakes

Assuming a level pipe needs no head lift. It needs about 1.3 m.

Stacking pumps together. Head lift does not add. Space them along the climb.

Treating sloshing as a bug. It is intended. Buffer around it instead of hunting for a fault.

Planning for exactly 600 m³/min. You will not reliably get it on a busy line.

Building a web of junctions. Every branch is another sloshing site. Prefer fewer, longer runs.

Piping a long climb because pipes are cheap. Count the pumps and their power first. Past a certain height, rail or a fluid truck wins.