Scope of Works

API was recently contacted by a water utility client in the UK. The utility had identified a leak on a Cast Iron pipeline in a traffic sensitive area. The client using traditional techniques could not fully understand the issue or pinpoint the leaks exact location.

Project Challenges

The pipeline is an old 9” CI pipe with 3 bar pressure and was installed over 50 years ago with unmapped location and configuration.

The client utilised an in house leakage team and searched for leaks over several months with the following methods:

• Noise correlators – 4 leaks identified along the main however, these resulted in 4 dry dig excavations
• Listening stick- Pipeline was sited below a busy traffic carriageway so this technique not feasible

This had a major knock on effect, as the client cannot proceed with a localized repair solution, and also may require a road closure of a main carriageway.

Upstream losses were identified as 2MLD however the client needed to fully understand its pipe configuration and also undertake a full internal leakage sweep.

Project Delivery

Images of site location

The client installed a through-bore style fire hydrant for PIPA to undertake an internal pipe assessment.

API uses PIPA technology that includes a pressure rated camera (HydrocamT2) and hydrophone tethered to a 100 metre semi rigid rodding to give the operator live video and recorded audio data during an inspection. The system enters a pipeline via a 1” tapping, and is fully chlorinated during its Insertion; the system works on a live basis, with no Interruptions to the clients services and with several surveys undertaken this unique product can cover a distance of up to 1km per day.

The technology is the latest live main inspection system on the market being fully battery powered and only requires a 2 man team for its Implementation.

During the survey a full leakage sweep was undertaken with no leak identified, however an unknown pipe branch was located with heavy water flow identified.

Video stills of survey findings

Survey results

• API successfully delivered a full leakage sweep of the asset
• API also identified an unknown 6 inch pipe branch (all were later validated by client)
• Tethered insertion technology system allowed for precise identification of the unknown branch location
• Acoustic system is very responsive and operator was able to identify that the missing 2MLD was not a leakage issue
• Client traced back the pipe branch identified and isolated a buried valve which in turn resolved the water loss issue

Conclusion

It would have been very difficult and expensive for contractor to find the remaining issues within the water main. The CCTV and acoustic capability proved indispensable for locating issues and trouble shooting.

API completed the inspection in 1 working day, and offered a full solution identifying true pipe configuration and also by ruling out leakage issues.

The contractor resolved the ongoing issue by removing the guess work at a fraction of the cost and time invested in other methods in previous weeks.

API Representative: The project was a great success, Ideal due to pipe location and material and also a great case study for our company. The contractor had exhausted all other pipeline inspection avenues, and was more than relieved when we offered a solution.

API has also delivered successful projects with the majority of the UK water utility companies.