Evaluation of Electrofusion Joints Strength of Polyethylene Pipes for Gas Distribution [PE]

The most popular and applicable method for connecting polyethylene (PE) pipes is to use heat fusion (HF) and electrofusion (EF). To remove chemical degradation, sand contamination, and water drop adhesion at a pipe surface, scraping the pipe surface and cleaning it with a wetted wiper including ethanol called PE cleaner are generally important for EF joints on the work site. Although the peel test using a test specimen cut out from an EF joint was conducted for evaluation of installed pipes as a quality control test, the effect of water drop adhesion at a pipe surface could not be evaluated along the whole fusion length of an EF joint. The water drops were vaporized during the fusion process and holes appeared along an embedded wire on the electrofusion interface. The tensile test using a test specimen cut out from an EF joint was conducted for evaluation of the EF zone with a water drop adhesion. It was found that the fusion strength at the electrofusion interface decreased with the total defect length. The allowable total defect length for EF joints was suggested.