TPT September 2015

Technology News

Pipe robots for the internal grinding of welding seams

THE machining of weld seams is necessary everywhere that, during the course of quality assurance and safety, weld seams are subjected to high stresses. Inspector Systems specialises in the development and production of self-propelled, tethered pipe robots for the interior inspection and non-destructive testing of complex pipeline systems, as well as offering technologies for interior machining. The basic structure of all the robots consists of several drive units with special rubber-coated wheels that are flexible and connected to each other and to the testing or machining module by a set of folding bellows. This modular design ensures a high degree of bendability and allows an insertion into the pipe system even when small amounts of space are available, such as with open armatures and flanges. Thanks to pneumatic pressing of the rubber wheels against the inner wall of the pipe, the robot gets centred/ stabilised and is able to drive through bends 1.5D as well as horizontal and vertical sections in particular of so- called ‘non-piggable’ pipeline systems. With its unique grinding robot technology, approved by renowned international companies and expert organisations in the offshore, oil and gas and nuclear industry, Inspector Systems has the technical knowledge to competently grind welding seam connections from the inside. Apart from the removal of weld undercuts, the qualified two-step OFTEN when clamping, there is not enough space to use a long lever, which results in the purchase of expensive specialist tools that are only needed once or twice before being discarded. A more logical solution in such cases has been designed by German company ENEMAC. The power-clamping nut ESB has an integrated planetary gear that can be easily driven by a small nut outside the housing, so that the internal thread is retracted, resulting in the counterpart being tightened.

Pipe robots for welding seams

of 0.1mm. Beside the fabrication of robots, Inspector Systems also provides services worldwide. Standard robots from inner diameter 75mm to 1,200mm are available for visual inspections combined with possible laser measurements for online defect sizing and evaluation of the interior pipe ovality or weld seam profiling. A 100 per cent determination of the wall thickness or detection of pitted areas can be done using available ultrasonic robots. Customised robots can be produced.

process (grinding/polishing) eliminates surface cracks as well as corrosion areas or any other kind of debris and defects. Additionally, a prevention of surface cracking is provided and a conditioning of the misalignment between pipe ends can be performed. Once the robot has reached its location inside the pipe, the grinding module is fixed by a clamping system. Controlled by an on-board grinding camera, a powerful three-phase current motor with changeable grinding disc mounted on a rotating unit (380°) and a radial stroke makes it possible to machine local areas point by point with an accuracy The principle is simple but the effect is significant because a force of 6-20t can be manually achieved by a single worker. The user screws the power clamping nut on to the existing bolt, then rotates at the top mounted nut with a standard torque wrench. In individual cases this can be achieved with a normal socket wrench. The series ESB is intended for large work pieces or tools, since the depth of screw is limited by the blind hole. The model is obtainable for thread of M12 to

Inspector Systems GmbH – Germany Website: www.inspectorsystems.de Simple, fast clamping of large parts

M64 and is also available with special threads on request. For power clamping nuts that are exposed to extreme heat there is a high temperature version available, which can be used in foundries or ceramics manufacture. The power clamping nuts can be used at any time, whether as original part or as a retrofit item.

ENEMAC  – Germany Email: info@enemac.de Website: www.enemac.org

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S eptember 2015