Since 2006 INSPECTOR SYSTEMS, in collaboration with ApplusRTD, has been checking the extensive district heating pipeline network in the Dutch metropolis of Rotterdam. The district heating pipes of the energy provider ENECO are laid under the ground and in some cases pass under heavily used roads, tunnels, rivers, metro and underground railway lines.

The project in the Netherlands was continued in the summer of 2013 when a section of district heating pipelines measuring around 300 metres in length underwent a thorough inspection. In practice, for INSPECTOR SYSTEMS this meant checking the section all over for any external or internal damage with a special ultrasonic inspection robot.

The ultrasonic inspection robot used is equipped with 32 ultrasonic sensors. The inspection head carrier is adjustable which allows it to be precisely adapted to fit the pipe diameter. To ensure coupling of the ultrasonic signal, the section of the district heating pipeline to be inspected was flooded with water.

The areas with a reduced wall thickness due to corrosion that have been detected in this way over the past eight years could then be repaired in a specifically targeted manner. As a result it was possible to avoid the replacement of the pipes to a large extent, which in turn led to a considerable saving in costs for ENECO, the energy company operating the district heating network of the second-biggest city in the Netherlands.

Further inspections of the district heating pipeline network in Rotterdam are being planned for the future.