For those of you off-topically talking about steam boilers: Liquiducts can actually transport a whole lot of steam (which is a gas, after all). The boiler, however, can only output two industrial steam engines worth of steam per pipe connection- so a liquiduct network that connects to nine of the boiler tank blocks will be able to send all the steam produced by a 36HP boiler through a single liquiduct to an array of engines.
For the on-topic people talking about moisteners: I should note that item loaders unloaders will not only power the track facing it, but also any other tracks adjacent to the loader/unloader, meaning that the cart might not actually stop if you have just the wrong configuration.
Let me try to explain: A chestcart comes up on top of an unloader above the moistener (or any other machine, for that matter), unloads its seeds/cobble/stone bricks, and is pushed off by a holding/boarding track. It then immediately rolls onto a downhill holding track atop an unloader on the side of the moistener. This track, however, is adjacent to the other unloader, and is thus powered, so the second unloader has very little time to unload wheat. I've found that in this situation, a wooden booster track in place of the second holding track will slow the cart more than any other track I tried; but simply running the cart in the other direction (unloading wheat to the side of the moistener BEFORE unloading seeds/cobble/stone bricks to the top) solves the problem entirely.
If you really want to use Redpower here, you might be able to tube items into a Railcraft Item Unloader directly (without any actual minecarts), which will then properly obey iSidedInventory. You might even be able to tell the unloader to keep one stack of wheat supplied, which would solve the problem of stuffing too much wheat in the moistener (making it not work) as well.
As a final note, Thermal Expansion adds Tesseracts, which are basically teleport pipes.
