I know the developers have their focus in getting survival done. And that pipes will be considered after that point. I would like to put forward a thought for how it could be done.

A pipe system can be a combination of two things, the pipe its self and a series of pinned (locked to the terrain) connectors. Each connector as a pinned object much like the foundation blocks or machines. In fact foundation blocks can have pipe connections to allow some one to walk over them using a ramp and platform.

Connectors can vary from simple inline connectors that are one to one. To more complex sets of splitters and mergers allowing materials to be split off or multiple sources to be merged. The Foundation blocks with connectors in them can also have many connections or could be configured by the user.

Connectors are smart, connectors should be able to connect with the colonies information network to be adjustable. Flow control could be used as a way to balance a system to one machines is not getting more than it needs. This also means that a damaged or broken pipe can leak when damaged and will require a player to take action to prevent the loss of resources.

Pipes on the other hand are simple. They are a standard A to B arrangement. They are made as a compact unit, to deploy one, the player will first choose the first attachment point be it a machine, base component, or Pinned Connector. The player then walks the pipe to the second connection point.

Pipes are rigid bodies, they will not flex when intersecting terrain and will break if they intersect terrain. So it is best to use pinned connections when the terrain bends to much. If you have used KAS from Kerbal Space Program, this will be familiar.

The pipe its self is three objects in the world, a pair of ends and a procedural body. The ends of the pipe are a static size, while the body of the pipe can be be stretched up to a maximum length (10m may be).

Some random thoughts:
Foundation Connector Inventory: Foundations could be altered so that they contain an inventory. The inventory would only accept connectors. Each inventory slot relates to a specific position in the foundation, this way a foundation can be customized with out needing to have 40 different foundation types.

Raised Pipe Way: The raised pipe way is meant have the pipes exist overhead instead of on the ground. The benefit is it has a lot of clearance. The downside is large vehicles may not be able to go under the pipes as a collision can occur. The raised pipe way could also have the same inventory options as I suggested above.

Wrench: Used to attach pipes to connectors, this tool is just a simple hand held wrench. Using a wrench instead of the standard assembly tool give a small amount of safety when putting things together or moving tanks when in proximity to pipes.

Pipe Connector Types: Some thought for this would be Pass Through, Split/Merge (2/1), Split/Merge (3/1), Cross over (Some times you need two pipes to cross in different directions using a single connector.

Pipe Connector Options: The main option for this is flow control. The purpose of this is to make sure resources can not back flow into a system and to make sure the connector directs the right amount of resources to where you want it. This can allow complex systems with out needing multiple pipes systems. Flow control is also used to designate what resources is being transferred from a Pipeline.

Pipeline: A pipeline is a set of bundled pipes that can be deployed to reduce the number of objects in the world. It is larger than a normal pipe but can carry up to nine different resources. Pipelines can not connect to machines and must have resources added and subtracted using standard pipes. 1-1 connectors can be used to pull resources from the pipeline by setting the desired resource in the connector.