Before this page gets fully fleshed out, here is an initial example of how to make a circuit for mana power (or elemental power). As you can see, when placing the Mana Pipe, a connector is automatically added to the enchanter. This doesn't happen at the magic Forge. And this is because none of the magic Forge's recipes require any form of mana or elemental power. Instead they require the crystals themselves, which you need to supply with a normal belt instead of a Mana Pipe.
It needs to be noted that the game is currently bugged and you need to click the Display Mana Pipe Overlay in the bottom right hand side of the screen after selecting the mana pipe to lay the correctly.