I need to point to this topic: https://forums.factorio.com/viewtopic.php?f=80&t=24061 New Types of Belts (NOT!)

And basically, what you want can be done by using splitters in more or less complex ways or (as already mentioned) more or less circuit logic.
It's not a new belt type per se, it's just ...

bobucles wrote:Can you not do this with smart inserters and combinators? It's a hell of a trick to pull off though. Better off just letting the raw materials fill everything up.

Yes, but I'm not going there since i'd be faced with medium spitters before I could wire up ammo feeding.

Right now the belts are just a transporter, you drop items on them and they travel down the lane until the end, resting atop until packed away.
even with filtering inserters there may be situations where one assembler or refinery gets all their resources snatched away from it's neighbor.

I suggest ...

I don't have a direct solution for the need for a wellhead pipe, but you could use a Module system, and have a limited number of slots, and modules of different "lengths", and have an auxiliary factory (or make them in an Assembler) to make Wellpipe Modules
I was thinking of a dynamic circle ...

it actually is possible, but I suck at pixel art and they would probably end up looking like habo hotel or something.

I know there's the hot spring mod, but using those springs you have to use oiljacks and pollute the environment - plus you also have to run on coal until liquid handling is researched.

Also, I feel that mod is kinda backwards.
Hot springs boil water with geothermal energy, even direct contact with ...