INSPECTOR SYSTEMS, in collaboration with Kontrolltechnik GmbH, has in recent years developed various SLOFEC eddy current inspection robots for GE Inspection, one of the world’s leading technology groups based in the USA.

With these inspection robots the company inspects various underground gas and oil pipelines at particularly critical points in the vicinity of tank stores or where they traverse roads and rivers. Key to this is that with the SLOFEC eddy current method local reductions in wall thickness due to corrosion, erosion or pitting can be detected without the pipelines necessarily having to be cleaned.

In mid-2013, on the basis of the exceedingly good test results, INSPECTOR SYSTEMS was awarded the contract by GE Inspection Services to expand the SLOFEC inspection robot range in collaboration with Kontrolltechnik GmbH.

SLOFEC eddy current robot inspects in uncleaned pipelines

Previously the largest possible inspection diameter was 30 inches. With the drive system newly developed in 2013 for the diameter range 32 to 48 inches, SLOFEC inspection robots from 32 to 48 inches are now available. The newly developed drive system consists of three drive units which are connected to each other by means of flexible bellows.

This tried and tested concept allows even the largest of the drive systems developed by INSPECTOR SYSTEMS to travel through pipe bends with a bending radius of 1.5D and to overcome inclines. The drive units in this model are fitted with an all-wheel drive. The drive system is therefore driven by a total of 12 direct current motors. With the all-wheel drive the systems achieves an unbelievable tractive force of more than 1000 kg. Depending on the number of bends in the pipeline system and the properties of the inner surface of the pipes, distances of up to 500 m can be inspected. The drive system is also designed so that it can move through dry, partially or completely water-filled pipes. It is therefore completely waterproof.

The results obtained with the all-wheel drive of the newly developed drive system for the diameter range 32 to 48 inches were very satisfactory. Consequently, in order to increase the tractive force, in the coming years and also where required, INSPECTOR SYSTEMS is planning to equip the smaller drive systems with an all-wheel drive as well.