Non-destructive testing of PE pipe joints

摘要

Butt fusion and electrofusion (EF) are the two main methods for welding polyethylene (PE) pipes. Both systems are used in the water and gas industries for distribution pipelines. Generally the larger pipes are joined using butt fusion and smaller pipes are joined with an EF weld. Typical flaws in the manufacture of these joints are contamination, lack of fusion, lack of penetration (EF joints only) and insufficient heat applied to the joint. These flaws can result in a joint that, although apparently fused, has reduced mechanical properties compared to a properly prepared joint. This paper presents ultrasonic inspection methods for detecting flaws in both butt fusion and EF pipe welds. Results of laboratory experiments on sample pipe joints and the development of prototype systems for application of the techniques to site work are described.