The Pressure Resistance tube is a special versions of the Pressure tube and a parts of another transport system of Project Red, which operates with air pressure. This pressure is created instantly if the connected Item Importer or Filtered Importer is activated by a Redstone signal. This pressure then transport items from different machines, e.g. the Block Breaker, or chests to another machines or chests (example shown in picture 1).
The Pressure Resistance tube is an option to control the routing path of transported items. It change the ranking of the possible paths. An example is shown in picture 2 and 3. Both pictures display a tube system to transport items from the chest on the bottom right to the other chest. But in picture 2 two pipes are replaced by Pressure Resistance tubes. This replacement changes the ranking of the paths which are actuated, so the paths are used as last, after all paths without Pressure Resistance tube. If more than one path with Pressure Resistance tube exists, then applies here again which path is the shortest one to the next free block with inventory.
Picture 1: Example of a tube system from Block Breaker (left) about the Item Importer (middle) till a chest (right) connected with Pressure tubes.
Picture 2: Example of a tube system with Pressure tubes to transport items from the chest on the bottom right to the other chests.
Picture 3: Similar tube system like picture 2 but the Pressure Resistance tubes on the two chests change the path ranking.