What it does:
This mod adds in extended underground pipes in length of 2x, 4x, 10x, and even 25x. The recipes for these merely involve using multiple underground pipes in the amounts shown and some iron plates IE. 4x Underground Pipes requires 4 underground pipes.

Where it comes from:
This mod was originally published by Swadius (https://mods.factorio.com/mods/Swadius/Longer_Underground_Pipes), then continued by enlow (https://mods.factorio.com/mods/enlow/Long_Underground_Pipes) and was just made 0.16 compatible by Dr_MarkEy
i make better view icons and fix crash on startup.