USE OF LARGE DIAMETER POLYTHENE PIPELINES BY BRITISH GAS.

The paper discusses the development of a PE system with large diameter pipes and the reasons for the change from established design concepts of ductile strength and stress cracking, to a design based on fracture propagation. Each of the three design concepts are examined leading to a determination of the design stress applicable to each pipe diameter. Certain aspects of the technology required for installation are also discussed with emphasis placed on the problems associated with fusion jointing the pipes.