Development and validation of an automated ultrasonic system for the non-destructive evaluation of welded joints in thermoplastic storage tanksMalcolm Spicer, Fredrik Hagglund and Mike Troughton (TWI)

Inspection techniquesFillet welds

Closed membrane water Beam plot for vertical fusion wedge probe housing face

Inspection techniquesButt welds

ResultsFillet welds

B-scan in vertical leg with 11 inserted aluminium discs

The sample with 25 aluminium discs

B-scan in horizontal leg with 14 inserted aluminium discs

ResultsButt welds

B-scan in skew 270 for a sample with 5 aluminium discs

The sample with 10 aluminium discs

B-scan in skew 90 for a sample with 5 aluminium discs

Scanner

Concept design

Project objectives

■ Develop non-destructive evaluation (NDE) techniques for testing welded joints in thermoplastic storage tanks and vessels

■ Create a database of critical defect sizes for different joint sizes that reduce long term integrity

■ Use short and long term testing to develop acceptance criteria for flaws in welded joints

■ Design and develop an NDE system for the reliable volumetric examination of plastic tanks and storage vessels

Software

Screenshot of the bespoke analysis software

Manufacture of welded samples containing idealised flaws

Double-V butt and fillet welds

■ Lack of fusion between extrudate and parent material ■ Cracks in parent material and through the extrudate ■ Cold weld between extrudate and parent material

This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 313950.