NDT techniques used in HDPE fusion joints

Part 1 Non-Destructive Testing of Fusion Joints of PE100 Pipes and Fittings The integrity and performance of PE100 pipelines are significantly influenced by the quality of their joints. The most prevalent methods for joining these pipes are butt fusion joining and electrofusion joining . Butt fusion joining is widely favored for its ability to create strong, continuous connections by heating the pipe ends and pressing them together to form a monolithic joint. Variants in butt fusion...

TWI has been carrying out research and development on non-destructive testing (NDT) using volumetric inspection techniques required for welded joints in PE pipes since the 1980s [12-22], which has culminated in the PolyTest phased array ultrasonic testing (PAUT) system ( www.polytestsystem.com ). The following description is based upon this particular system of PAUT. Conventional ultrasonic inspection uses a single piezoelectric element probe to send ultrasonic waves, typically at frequencies...

Microwave Imaging (MWI) inspection is unlike many other NDT techniques in that it is does not have a history of use for metallic materials, for which it is unsuitable, but has been specifically developed for polymeric materials based upon measurement and changes in relative permittivity. It uses a form of electro-magnetic radiation (EMR) in the microwave frequency range between 1GHz and 100GHz (Figure 1). Figure 1. Position of microwaves used for inspection within the range of EMR The use of...

It has been established that NDT techniques can be successful in detecting flaws within fusion welded joints, but independent scrutiny is required to establish to what extent the flaws detected are significant in terms of performance of the joints. This can only be established by comparison of results of NDT analysis with destructive mechanical testing currently specified to identify satisfactory performance of the joints. A number of studies have been identified where controlled...