PRO AQUA Terra smooth-wall pipelines are used in external non-pressure sewer networks. The pipes have a ring stiffness of SN4, which allows them to be laid without the use of additional protective devices. Pipe diameters range 110 to 200 mm. PRO AQUA Terra sewage pipes and fittings have improved chemical resistance, high resistance to hydroabrasive wear, low roughness, lack of corrosion and ease of installation.