Pump
Small pump (when powered) moves fluids from its input to its output and (regardless of power) prevents the opposite from happening. This happens even if the pressure of input is much lower than the pressure of output (although speed may be affected). Note that pump can't mix different kinds of liquids.
The small pump can eventually be seen as the "inserter for liquids".
Throughput (needed number of pumps)
The throughput depends on the pressured-difference between input and output.
In the worst case (no input pressure, max output pressure) you need 5, better 6 small pumps, to fill a pipe to it's max. throughput capacity. See http://www.factorioforums.com/forum/viewtopic.php?f=5&t=6066
Using as Valve
The small pump works as a valve:
- When powered the small pump will let liquids through, but only in it's set direction. The throughput depends on the pressure, see above.
- Tip: You can just rotate the pump to "switch a pipe off". This is sometimes handy.
- If unpowered the small pump doesn't let anything through.
- This can be used to control some parts of your factory (but currently it is very complicated).
An example, which uses some habits of the pump can be found in the forum.
| Recipe: |    |
| Total raw: | |
| Pump speed: | 0.5 |
| Max Power | 30kW |
See also