If you depend on flamethrower turrets or water turrets for your defense, the pipelines supplying them with ammunition are your point of vulnerability. This mod provides pipes reinforced with concrete and steel, and coated with plastic. They are quite expensive to make and you need to research some other technologies before you can research hardened pipes. However, the hardened pipes come with some very strong resistances against physical damage, explosions, fire, and acid. Moreover, they are immune to impact, so you won't accidentally destroy a pipe if your vehicle collides with it -- only your vehicle will take damage!
Hardened pipes/underground pipes can connect to vanilla pipes/underground pipes.
You can set the maximum distance covered by hardened underground pipes (range: 9 to 20 tiles) using a startup option. The amount of ingredients needed for hardened underground pipes is linked to the maximum distance.
You also have the option to simplify the ratio of assemblers for hardened pipes to assemblers for hardened underground pipes. If you use the easy ratio, the time needed to produce one pair of hardened underground pipes will be extended so that one assembler for hardened pipes will be able to supply one assembler for hardened underground pipes. This allows for easier setups -- but because it will take longer to make one pair of hardened underground pipes, you will need more assemblers in total to produce the same amount (2*x instead of 1+x).