Surge and Fatigue in uPVC Sewer Rising Mains

The causes of surge in sewer rising mains are discussed together with failures experienced in uPVC pressure pipes used for rising mains. These are related to laboratory data on the dynamic fatigue strength of uPVC pipe material Steps taken to limit surge pressures to safe limits in new and existing installations are detailed. Problems arising from partial vacuum conditions, the interaction of surge-induced dynamic fatigue stresses and local stress raisers and from cumulative fatigue damage in pipes after the introduction of surge control are considered