Adds pipes with restricted connections, and several useful valves.
Mods introducing new content into the game.
Augmented or new ways of transporting materials - belts, inserters, pipes!
Instead of having to craft all different types of pipe pieces why don't you use placeable_by = {item = "pipe", count = 1} ?
placeable_by = {item = "pipe", count = 1}
I've tested and added that in 3.1
