System Pressure Rating & Residual Life # 2004 Milan
Ipswich Water commenced reviewing the service lives of different pipe materials in its gravity sewer system. Unlike other pipe materials, PVC sewers did not have failure histories, or deterioration revealed in CCTV inspections, even after 25 years of service. Therefore establishing a realistic predicted life was not possible using statistical analysis of historical field failure data. The approach taken was to exhume a number of elastomeric seal jointed PVC sewer pipes that had been in service for periods of up to 25 years. The samples were tested for selected mechanical properties and joint performance characteristics which might be considered age dependant. The results indicated there had been no deterioration in the material and the joints continued to meet current performance specifications. Two methods of quantifying the condition of PVC sewer pipelines and predicting the residual life are suggested. Based on this analysis, the pipelines examined have not exhibited any significant deterioration and should provide many more years of service.