The long-term performance of plastic pipes, particularly those installed underground, is significantly influenced by creep. Creep is higher for Polyolefin (PO) materials compared to PVC.
For buried pipes, creep plays a crucial role. In non-pressure applications like sewers, the relaxation of tensions under constant deformation is a main factor. This state of constant deflection is observed in flexible buried pipes after soil settlement occurs. Creep can also affect the long-term tightness of rubber ring joints, especially in pipes with thin sidewalls from deep profiles, as it can lower the contact pressure required for the elastomeric seal.
This property difference is particularly relevant for buried pressure and non-pressure piping systems, including sewers and drainage where soil loads and sealing integrity over time are critical.