Rawwater provides leak and defect sealing solutions using low melting point alloys called M3. Rawwater’s proprietary technology includes M3Spray in which molten alloy is sprayed directly against a flowing liquid leak to stem it.
Building on the leak sealing feasibility work carried out previously, the project will focus on the testing of Rawwater’s M3Spray for sealing realistic transformer leak scenarios, including on decommissioned transformer parts. Deployability of the solution including access nozzle development for manual application and semi-autonomous robotic integration for controlled deployment will be tested. Alloy containment to ensure that metal particulates are contained and controlled will also be tested.
This work will culminate in a pilot deployment on a transformer (TRL7) on the NGET estate. Following an initial period of 3 months, there is the option to extend the project to include further robotic integration and further scenarios to a wider range of leaks.
Benefits
National Grid procures an increasing amount of mineral oil for top up purposes every year. Fixing the oil leaks will not only reduce the oil requirement but beneficial for overall asset lifecycle health. Fixing the leaks will reduce the mineral oil top up requirements, maintain health, reduce travel to substations (Scope 1 emissions), and maximise the network capacity by reducing the maintenance outages on transformers and other assets. Transformer replacements in RIIO-T2 period is budgeted at over £240M. Savings made due to spend in T1 on asset life extension is £97M. If more transformers can operate longer than currently planned, significant savings can be made, orders of magnitude above the spend of this project, and the end solution.
Learnings
Outcomes
2024/25
Rawwater’s M3Spray was confirmed as a viable technique for future adoption for transformer oil leak sealing during Phase 1. Phase 2 work initiated to further develop the application of M3Spray to address a wider range of scenarios.
Recommendations for further work
- Identify and agree suitable test scenarios with a focus on flanged connections/bolts.
- Capture requirements to enable the use of M3Spray in a wide range of NGET site scenarios, including the potential for non-outage applications.
- Develop a more generalised M3Spray manual application solution, including containment.
- Test and demonstrate the manual solution.
- Develop a concept for a remote application solution which has the potential to be used in a non-outage or in a short outage leak sealing scenario.
- Plan for controlled oil testing to evaluate the impact of application of M3Spray in a range of scenarios.
Lessons Learnt
2024/2025
Pilot candidate identification and selection was challenging within project timescales. Selection of a pilot asset within an enclosed space provided operational access challenges. Prioritising a successful pilot narrowed the wider applicability of the Phase 1 approach.
Learnings were gained on the level of manual intervention required for the robotic deployment. The gap to a fully remote system proved to be larger than anticipated, but also dependent on the transformer deployment type and access restrictions. The criticality of spray positioning for repeatability favoured a robotic placement over manual.
The collaborative approach allowed for open discussion of any changes, issues identified or resolved, and site constraints as they arose, enabling a plan to be agreed upon in line with the overall project aims.
While outside of the scope of this formal proposal, further scope could explore M3Spray automation to prepare for wider pilots and eventual roll out across the network. This would take the form of a robotically controlled elevated work platform and a robot with enhanced automation capabilities, to cover a wider range of access environments. Detail to be agreed upon project confirmation. This would result in TRL 8 level technology.
Dissemination
2023/24
A poster presentation at Energy Innovation Summit in Liverpool in October 2023. The project was displayed again for other utilities at the Innovation Zero Event in London in May 2024.
2024/25
An oral presentation at EuroDoble 2024 in Manchester (7-10 Oct 2024) discussing the outcome of the project.
