A Method for Detecting the Cold Welding and Optimizing the Welding Procedure for the Electro-Fusion Joints in PE Pipes

Electro-fusion (EF) joints are widely used in polyethylene (PE) pipes connection. In the paper, a method for assessing the cold welding and optimizing the welding technology for such joints is developed. An Eigen-line in the EF joint is observed by using the phased array ultrasonic focusing technique as well as B-scan real image technology. A method called “Eigen-line method” is developed to assess cold welding with an empirical formula by measuring the distance between the line and metal wires. A lot of tests show that the developed method can be used to assess the welding technology by measuring the moving speed of the Eigen-line and the distance between the line and metal wires in UT real-time video. Based on UT real-time video experiments, the optimized welding prcedure for joints is obtained, which greatly reduce the time and cost in development of EF joints in PE pipes.