Wikia

The Stone Waterproof Pipe can transport Water, Lava, Oil, and Fuel. It can be used to move these fluids between machines and Tanks. Fluids cannot move into a pipe that is not waterproof.

Stone Waterproof Pipes do not connect to Cobblestone Waterproof Pipes. By using both types of pipe, networks can be built in confined areas, however both Cobblestone and Stone waterproof pipes will connect to other types of pipe such as Gold, Iron, or Wooden Waterproof pipes. They function in an identical manner to normal stone pipes, but with liquids. They can not be used to extract liquid from bodies of liquid or from tanks.