Pigs for unpiggable pipes

Pipelines serve important functions for countries and citizens. They also represent a significant investment on the part of owners, typically specialised distribution companies with limited technical and engineering expertise. Maintenance and inspection are complicated, so robotic devices called pigs are sent down to flow through the pipes and perform various operations.

These pigs are evolving thanks to EU support of the project PIGWAVES. Scientists are developing pigs sporting long-range ultrasonic testing (LRUT) technology exploiting guided waves. They will conduct faster, cheaper and more accurate total-volume inspection in pipe segments of about 50 m in length.

Every 50 m, the robot will expand a probe collar and lock itself to the pipe. The collar will utilise the LRUT technology to map the circumferential and axial pipe corrosion and cracks. It will be able to inspect 50 m in a few milliseconds and reduce the amount of data stored by several orders of magnitude. The robotic pig will demonstrate one more step in its evolution: the ability to swim. In addition to freely floating around sharp bends and past debris, it will be able to swim if there is no current flow in the pipes.

Team members have developed all system specifications and inspection procedures and completed the majority of designs. When it is finished, the tool will be applicable to previously non-piggable as well as to piggable pipes, greatly expanding utility.

The PIGWAVES robotic pig is thus expected to have major impact on the safety of EU pipeline infrastructure and the security of the products it carries. This will have the side-effect of encouraging pipeline use as an alternative to vehicle transport, contributing to a reduction in harmful emissions.