Access Extension Pipe

The Access Extension Pipe allows devices to access a block's inventory and other properties, without being placed directly next to it.

Usage

In order to give a Block B access to the properties of a Block A, place the first Access Extension Pipe next to Block A and from there place a connected line of pipes towards Block B. Each pipe segment should then show a green-purple connection towards Block A.
If a pipe segment faces the wrong way, it can be rotated by right-clicking it with an empty hand.

It is also possible to branch out the pipe structure to let multiple devices access the same block.

Note: These connections are only one way, that means Block B can access Block A but Block A can not access Block B, instead if it tries to interact with the pipe attached to it, it would actually access itself (which you might want to avoid in most cases).

And sides are handled so that, when Block B is placed below an Access Extension Pipe it will also access Block A as if it was placed below it, even when the pipe attaches Block A on a different side.

General Mechanics

These Pipes utilize the Forge Capability system which is commonly used by TileEntities and other game objects to provide access to their properties. For example item inventories, fluid inventories and Forge's own energy API are all accessed via this capability system (and mods may use it for other things as well).

So the way these Pipes work is that, when devices attempt to access the capabilities of Access Extension Pipes, these pipe blocks simply forward that access attempt on to the block at the end of the line (Block A) and provide it's capabilities instead of their own.