Specifically, is there any particular reason why Alloy Processing 1, which unlocks bronze pipes, doesn't require Advanced Bronze Smelting 1, which gates the Bronze Plates that the pipes are made from?

Edit: damn, i can't change a thread's title after posting it... I initially wrote about the item's ingredients, but changed the phrasing and now there's a grammar error highlighted on the Discussions page... :-s Is there some kind of moderator-level access to fix that?

Advanced Bronze Smelting 1 isn't from my mod... sounds like you're using someone elses mod that does strange things to the tech tree.

in bob's mods, Alloy processing 1 unlocks Bronze plates too.