Case Studies # 2001 Munich
In the Netherlands, a gas distribution system of Ductile PVC with elastomeric sealing ring joints and several special features is already operating to full satisfaction during more than 35 years. Today, Ductile PVC is the preferred material in this market. The total length of the gas distribution net is about 110.000 km An investigation has been carried out to evaluate the experience with the Ductile PVC system with respect to safety in use, failure characteristics, remaining lifetime and economy of the system. The used material is a mixture of PVC with chlorinated PE that results in a very ductile material and a good resistance to gas components, notching, point loading and catastrophic failures. Several features in the system make it very attractive for the user with regard costs and safety in installation and use. A recent cost analysis has shown that especially the installation costs of the Ductile PVC system are significantly lower than for the PE system. Statistical information has shown that the repair frequency of the Ductile PVC system is far the lowest in comparison with all other materials used. From excavated pipe and joint samples that have operated up to more than 40 years, it has been shown that they still perform very well with a sufficient high level of reliability.