Plastic Pipes Conference Association # 2012 Barcelona
Troughton Mike
The current practice for assuring the quality of butt fusion and electrofusion welded joints during installation is by recording the welding parameters used, together with a visual inspection of the welded joint, supplemented by the destructive testing of welds on a sample basis using a short-term test. However, visual inspection can only examine the external surface of the pipe weld; it cannot provide evidence of embedded flaws or a weld with incomplete fusion or cold fusion. In addition, cutting a specimen from a weld for mechanical testing and then replacing it with a weld of unknown quality does not ensure the integrity of the pipeline. Volumetric nondestructive testing will not destroy perfectly good welds and has the added environmental advantage of reduced waste. This paper describes an ongoing European-funded project to develop ultrasonic phased array techniques for the inspection of both butt fusion and electrofusion joints in polyethylene pipes of diameters between 90 and 710mm (3.5 and 28 inches), and to determine critical defect sizes and particulate contamination levels using accelerated long-term testing. Keywords : polyethylene, butt fusion, electrofusion, inspection, ultrasonic
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