Tue, 26 May, 2026
We are holding a launch meeting for a new joint industry project (JIP) dedicated to the production of flawed butt fusion joints in polyethylene (PE) pipes for the evaluation and qualification of ultrasonic non-destructive testing (NDT) systems.
The publication of the ISO Technical Specifications, ISO/TS 22499 and ISO/TS 24399, as well as the increasing number of organisations providing ultrasonic NDT of butt fusion joints in PE pipes has been gaining momentum. However, the ultrasonic inspection of PE joints is very different from the inspection of metallic pipe joints. The attenuation of the ultrasonic signal is much greater in PE than in metals, the velocity of the ultrasound is much slower, and the types of flaws are very different to those found in metal joints.
As a result, the methods used to inspect metallic pipe welds will not work with PE pipes. Instead, the ultrasonic probes, wedges, manipulators and procedures have to be designed specifically for non-metallic pipes.
The procedures for qualifying NDT procedures in ISO/TS 22499 and ISO/TS 24399 involve making 21 BF joints for each of four pipe wall thicknesses ranges. Five joints should contain no flaws and are used by the NDT provider to set up their equipment and procedures, while the remaining 16 joints are used for blind inspections - eight of which contain no flaws, two contain embedded lack of fusion flaws and six contain fine particulate contamination.
The production of these joints is expensive, making it costly for individual operators to produce the required test joints, especially if they need to cover the whole pipe wall thickness range from 8-100mm, which would require the manufacture of 84 joints. It can also be difficult and costly for operators to assess the performance of specific NDT providers.
To solve both of these problems, TWI has proposed the creation of a central library of flawed joints that companies can borrow as required. We are a world leader in the insertion of flaws into welded joints in PE pipes in a consistent manner and wrote the flaw insertion procedures given in the annexes of the ISO Technical Specifications, making us ideally placed to create and hold this library of flawed joints.
Interested parties can attend the project launch meeting, either online or in-person, on 3 June 2026. See here to find out more about this project:
https://www.twi-global.com/media-and-events/events-diary/production-of-flawed-butt-fusion-joints-in-pe-pipes