Factorio Forums

Exactly how powerful are Small Pumps relative to Offshore Pumps? I use a mod that lets me measure the charge in an Accumulator, and via that I can feed data into the wire network and use that to control power production by turning Small Pumps on and off.

But I get the impression that 1 Small Pump per line of 13-14 Boilers and 10 Steam Engines is insufficient. It's not clear, though. The one aspect of Factorio's interface that is confusing and non-transparent is power production and liquid flow.

(I know I can shut off the Water flow with the Offshore Pumps, but I think part of the fault of my old setup was that I shut off the Water flow before the Water arrived at the Boilers, and that it'd probably work better if I shut the flow off after the Boiler phase.)

Offshore pumps produce 60 water per second, small pumps can pump 30 water per second. You'll need to split the pipe into two pumps and then recombine it to accomplish what you're looking for.

If you want to verify this yourself, you can go look at the prototypes in demo-entities.lua (offshore-pump) and entities.lua (small-pump). The offshore has a pumping speed of 1 and the small pump has a pumping speed of 0.5. These are values per tick, and with 60 ticks per second you get 60/30 water per second, respectively.

Vin is correct. I've determined in game that each small pump will drive 5 steam engines, and that if you put them in parallel, two pumps will drive 10 engines.

It's actually not hard to test. If you have a steam engine setup running rather than idling, and a steam engine isn't getting 100% water, there's a "water" bar in addition to the two regular power-available / power demand bars. That bar can be very low and it will still work, but if it's black, no water, the engine provides no power.

So set up a line of 14 boilers, one small pump, and 10 engines. Look at the information on each steam engine. You'll see the water bar, and with each engine it drops until the water runs out entirely, and with it power. This should happen with engine 6, telling you that the pump is good enough for 5. Now add a second parallel pump, and the problem should go away.

As Vin said, you need to allow room for pipes before and after the pumps to split flow and recombine it.