Cured-in-place pipe (CIPP) is a trenchless pipe rehabilitation method. A resin-saturated felt tube made of polyester is inverted or pulled into an existing pipe. The liner can be inverted using water or air pressure. The pressure required for inversion can be generated using pressure vessels, scaffolds or a "Chip unit". Hot water, UV light, ambient cured or steam is used to cure the resin and form a tight-fitting, jointless and corrosion-resistant replacement pipe.