Underground pipes keep getting wrecked by absolutely any AOE damage, whether from enemy or any player explosive/fire weapons. Especially with mods like "Rampant" or "Explosive Biters" the pipes seem like made from wet cardboard. It also makes maintaining flamethrower turret lines a real chore.
Vanilla normal quality pipes have 100hp, these underground pipes for whatever reason have only 10hp. They're both equally exposed to AOE.