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!
Would you consider adding a valve that can be opened or closed with a signal? It would be handier than a pump for a variety of applications.
It's a popular request and I'd love to do it, but unfortunately it's not practical. A valve that reacted to circuit signals would have to be based on the pump, so would always attempt to flow at max rate when its condition was met.