The Pump can move any liquid (Water, Lava, Oil, or Fuel) through its thick input side to the thin output side, above the lights on the thick side there is a arrow indicating the way the liquid will flow, and as long as there is another Grate, connected with some Fluid Pipe, the liquid will flow out of it.
The pump itself requires Blulectric power (about 75v and 90A of power in one test) as well as a continuous redstone signal to operate. While the pump has enough power and a steady signal, it will continuously pump any liquid it can find on the input side.
WARNING: When pumping a non-viscous liquid, such as water or fuel, the pump tends to produce more liquid at the output than was present at the input. This may cause any storage containers to overfill, causing a significant cleanup job. The pump is very powerful and capable of filling large spaces with liquid in a few minutes.