TWI has an established reputation spanning over 25 years for technology development and project work in the welding, testing and inspection of plastic pipes for the utilities and nuclear industries. Expertise includes process and procedure development, independent assessment of new equipment, long term testing, standards development and determination of the significance of defects in welded joints. Plastic pipe welding and testing work at TWI addresses the needs of the huge global plastic distribution pipeline sector for gas and water, and also the large potential market of civil nuclear power generation. Polythethylene (PE) pipe is widely used but there remain significant questions over the long-term properties of welded joints and the significance of defects in joints. Recent advances at TWI in the non destructive and mechanical testing of PE pipe welds, means that all potential defects in both electrofusion and butt fusion joints can now be detected and flaw acceptance criteria can be determined.
The current challenges faced by industry include:
- Acceptance of welded PE pipe installations for nuclear applications.
- Validated inspection techniques and procedures.
- Life estimation.
- Flaw acceptance criteria.
- Upskilling installation personnel through training and qualification.
TWI has a proven track record in tackling all of the above challenges.
TWI possesses a comprehensive list of equipment for welding plastic pipes and for the inspection and mechanical testing of the welds, including IR lamp, vibration, laser and microwave welding equipment, phased array ultrasonic, computer tomography and thermography NDT equipment and a whole pipe tensile creep rupture test rig.
In addition to research and development TWI also offers training and qualification for individuals in the welding of plastic pipes. TWI staff represent the UK on a variety of European and International Standards Committees in this area, including CEN, ISO, ASME and AWS.
The TestPEP project is a European Collaborative project: Development and Validation of an Automated Non-Destructive Evaluation (NDE) Approach for Testing Welded Joints in Plastic Pipes.