Research on Ultrasonic Testing for Electro-Fusion Joint of Reinforced Thermoplastic Pipes

Reinforced Thermoplastic Pipe (RTP) is generally connected by butt fusion joint or electro-fusion joint with intensified sleeves. Contrast to regular electro-fusion joints for PE (polyethylene) pipe, those for RTP are of larger length and thickness. Based on the ultrasonic inspection research of electro-fusion joint of PE pipe, the authors designed a special phased array probe for the electro-fusion sleeve of RTP considering its complicated structure and large size. A special C-scan technique was proposed including a longitudinal scan carried out with electronic method and circumferential scan carried out with mechanical method. Meanwhile, special software was designed to ensure the synchronization and precision control between longitudinal electronic scan and circumferential mechanical scan, and the consistency control between ultrasonic information and position information. Based on the results of detection experiments of RTP electro-fusion joint with typical defects, it was proven that this technique has the capability to detect typical defects in RTP electro-fusion joint, and high testing sensitivity was obtained.