Plastic Pipes Conference Association # 1979 Brigthon
Price, Gray
The properties of HDPE pipe materials necessary to satisfy processing and performance requirements are considered. Methods of predicting pipe performance are discussed, and experimental data are presented to support the predictive technique.
High density polyethylene is now well established as one of the major materials for pipe systems.
The term high density is being used here to describe the rigid polyethylenes and includes the medium density materials introduced more recently. HDPE has been used for more than 20 years in a wide variety of applications ranging from pressure pipe in water distribution schemes and chemical plant to very large diameter non pressurised drain and effluent pipe installations. PE pipe is, however, still very much a growth industry as shown by the rapid development in recent years of MDPE pipe systems for natural gas distribution.
In the early days the design of pipe systems was based largely on empirical relationships obtained from pipe pressure tests. Nevertheless, these ideas have proved to be soundly based, as can be seen in the many successful, diverse applications. Today however there is emerging a better understanding of material properties. and design methods and this seems a good time to review the current state of knowledge on the selection and tailoring of PE materials and the design of pipe systems. This better understanding is vital to the development of markets for PE materials in the more demanding applications such as gas distribution now and in the future.
For many years too, it has been recognised that articles in plastics should be rationally designed in the same way as in traditional engineering materials. Pipe systems are one of the first applications where plastics are load bearing for much of their life and the design principles available for pipe systems should serve as a model for other applications of plastics materials.
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