World-first pipeline technology that will revolutionise performance and safety in industries around the world will be unveiled on 27 November in Aberdeen at the British Manufacturing and Fabrication Offshore Energy event
The development of the first-ever FSWBot, Friction Stir Welding Robotic Crawler for internal repair and refurbishment of pipelines, has been led by Forth Engineering in Cumbria
Sponsored by Innovate UK, Forth Engineering is working with consortium members TWI, J4IC, Innvotek and LSBU on the project.
The consortium seeks to integrate several technologies including friction stir welding, milling, patch deployment and ultrasonic NDT. Friction stir welding is a solid-state welding process which generates enough frictional heat to soften or plasticise the metal without melting it, allowing metal components to be forged together at the joint line.
This system will demonstrate that a patch weld can be made in steel pipe under oil and that a representative FSW system can be made small enough to operate in a 36-inch diameter export pipe.
The FSWBot is envisaged to be a five-segment or six-segment PIG type vehicle which will be inserted at the production end of the pipeline and will travel with the oil flow to a pre-designated spot to perform a repair.
One segment will carry the FSW machine and a steel patch dispenser, with the other segments carrying the navigation, control system, communications, NDT (non-destructive testing) and power storage/generation payloads.
On entering the pipe segment containing the pre-identified defects, the FSWBot will stop, then slowly advance until the FSW system is in place over the defect. It will then lock itself in place and confirm that it is correctly located to perform the repair.
An onboard turbine in a duct within the FSWBot will harvest energy from the oil flow within the pipe to augment any power cells carried on the system, with the duct providing through flow in the pipe.
Once energised, the FSW unit will deploy a milling tool to cut away the corroded area and prepare a pocket in the pipe wall into which a steel patch will be dispensed.
The FSW unit will then weld this patch in place and deploy the milling system again to ensure that the patch is flush with the pipe wall and will not initiate turbulent flow, nor impede the passage of subsequent cleaning or inspection PIGs.
FSWBot will then deploy NDT packages to inspect the weld for quality assurance before unclamping and moving downstream to repeat the process on any further defects.