Making the GRAID

In 2014 National Grid was awarded £5.7 million (US$6.94 million) by Ofgem through the annual Network Innovation Competition for its concept for a new-age pipe inspection device.

By Nicola Riggon, Communications Support, Project GRAID

Along with three SME’s, National Grid is set to change the face of asset management with the development of a ‘gas robotic agile inspection device’ – project GRAID.

The UK’s National Transmission System (NTS) supplies gas to nearly 11 million UK homes and businesses, which is why it’s crucial that National Grid has a robust strategy in place to maintain all 750 km of pipework. The construction of the NTS began in the late 1960s with a 40-year design life. Over 60 per cent of these assets will be beyond this point by the end of 2030.

Steph White PhotographyThe current asset-management strategy for this pipework relies on aboveground survey techniques and existing cathodic protection on the pipes themselves. As a result there is a heavy reliance on good design and construction practices having been applied to the original assets.

Currently, if corrosion is suspected, the only way to confirm this is through excavation, which is both financially expensive and environmentally adverse. Project GRAID will enable a proactive, risk-based approach to the management, maintenance, and replacement of these ageing assets.

The project highlights National Grid Gas Transmission’s commitment to delivering innovation that provides a more reliable and environmentally friendly approach to managing its assets and building value for gas consumers. Project GRAID – through future development of the robot – could save customers £60 million (US$73.11 million) over 20 years and
2,145 tonnes of CO2 per year.

National Grid has partnered up with Synthotech, Premtech, and Pipeline Integrity Engineers to develop a pioneering robotic platform which can negotiate its way through complex pipework geometries and varying gas flows while withstanding extreme pressures of up to 100 bar(g). The robot will act as a platform to deliver a high quality vision of the internal pipework with multiple cameras and a sensor package which will gather data on the condition of pipework, which has not previously been in-line inspected.

sandbox-robot-image-1The project aims to introduce a new era of launching robots into high-pressure gas pipework, enabling a proactive and evidence-based approach to the management of critical ageing assets.

Synthotech Ltd specialises in the innovations, engineering, and delivery of ‘must-have’ technology for the utilities’ industry. The team has a proven record of delivering innovative technological solutions and is responsible for developing the robotic platform.

Premtech Ltd provides expertise in engineering consultancy and design management for onshore pipeline and installation projects. The team is modelling the pipework of the selected trial sites to create routes for the robot, designing the launch and retrieval vessel and the testing facility.

Pipeline Integrity Engineers Ltd provides asset integrity and risk management services to the oil and gas industry. It is responsible for the project’s technical governance and assurance as well as translating inspection results into an asset-management strategy for the future.

Designing the robot

Stage 1 of the project involved the development of a 3D conceptual model to determine the best possible design for the robot. Now in stage three of five, the Project GRAID team has developed and tested various robot concepts to decide on a preferred design which will be taken forward into offline trials.

graid-beta2-psSynthotech has designed a modular robot which has the ability to carry an intelligent sensor package through the pipework and feedback data. Many factors have contributed to this current modular design, which will be piloted through pipework by a trained engineer.

An aerodynamic shape

The shape of the robot has been developed and refined through the vigorous research and testing of aerodynamics and high pressured gas flows. When gas reaches these higher pressures, the environment becomes much denser than air, much more like a liquid which is why earlier concepts of the robot were designed based on the shape of a dolphin, the fastest and most aerodynamic creature of the sea. The current robot design is to be encased in interchangeable curved shells dependent on the gas flows and pressures it will likely be against, to ensure maximum speed and agility.

A tracked vehicle

The robot will steadily make its way through the pipework with its uniquely designed tracks. As it crawls through the system, cameras will monitor the movement of the tracks ensuring functionality. Cameras also feature on the front and back of the robot for visibility of defects.

NDT & UMS

Between the two modules of the vehicle is a robotic arm which houses an intelligent sensor package. This arm will rotate to take readings throughout the pipe. Information can then be fed back to a specially designed control desk via an umbilical management system (UMS).

The UMS will also ensure the safety of the robot whilst inside the pipe. Should there be any issues, the strong armoured cabling will also act as a tether so the robot could be rescued from the outside of the launch vessel.

Launch vessel

As with traditional pigs, the robot needs access to the pipework. As a result, the team has worked with German-based engineers at RMA to design and build a launch vessel which will safely connect onto the NTS at selected trial sites and allow the robot entry. This launch vessel will also safely house the UMS system.

Now into its third phase, Project GRAID is well underway and progress is being made, with field trials set to take place in 2017, before the system is deployed by National Grid’s Pipelines Maintenance Centre in October 2018.

For more information visit the Project GRAID website.

This article was featured in the September edition of Pipelines International. To view the magazine on your PC, Mac, tablet, or mobile device, click here.

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