The pump is used to move chemicals, goods and items among Polycraft and Minecraft inventories. The pump must be place in a direct line of sight from the inventory you are pumping out of (i.e. no turns or kinks in pipes upstream of the pump). Downstream, the resulting Flow Network can be quite complex. Pipes which are place between a Pump and a Flow Regulator or between a Pump and Polycraft Inventories must be place facing upstream. The meta data values of pipes is important. Flow Networks will not work if the pipes are backwards. The pump tells you which targets are properly regulated and how many pipes are in the network paths.
If a Lava Bucket is used, the pump will also consume the bucket!!