Current regulations require that domestic drinking water is practically lead free, with levels not exceeding 10 µg/l (10ppb). Therefore, with an estimated 40% of UK homes still having their tap water fed through lead pipes, coupled with OFWATS increased regulatory requirements to improve customer service and avoid shutting down water supplies, these lead pipes now need to be replaced using under pressure solutions.
It is often commented throughout the UK water industry, that after burst mains, ferrule related jobs are often the biggest cause of planned shut offs, customer supply interruptions and therefore poor SIM performance.
The Arctic Driver® Ferrule Extraction System allows for the under pressure removal and/or replacement of an existing ferrule, while only isolating the specific customer having their lead service pipe upgraded to the current specification in around 20 minutes. Importantly, during this process, the rest of the network remains live. By adopting the Arctic Driver solution, water companies are improving customer service levels and reducing customer complaints. Hence, the achievement of improved SIM scoring must be seen as a long term sustainable benefit, which is derived by this new way of working. In addition, the removal of cut and capped old ferrules eliminates a significant risk of future back ground leakage and re-excavation to carry out leakage repair. By removing the need to shut off and drain down sections of main, water loss through drain down, recharge and the potential for knock on bursts, (which has been previously tabled at 63% of all network interventions over the following 7 days), the pressure equilibrium of the distribution network can be maintained, leading to a more optimal operational status. This also avoids the need for any further drilling of the main and potentially compromising its integrity.
The Arctic Driver process requires the lead supply pipe connected to the Ferrule to be squeezed off and therefore stop the flow of water. The ferrule is then secured throughout the operation by the Arrestor Clamp and then frozen by delivering liquid CO2 through the Freezer Shroud which has been placed around and fixed to the ferrule. This creates a solid ice plug inside the elbow of the ferrule and allows for the supply pipe to be cut off, leaving the frozen Ferrule stub within the Arctic Driver Shroud, over which the Golf Driver Saddle is then placed. Once the saddle has been secured around the pipe, the existing ferrule can be extracted under pressure. The patented Arctic Driver Saddle, has a unique isolation feature that allows the removal of the Artic Driver equipment and ferrule stub under pressure, to leave the existing drilled and tapped ferrule hole encapsulated by the Arctic Driver Saddle.
In the case of a service disconnection, the saddle can be capped off using a brass plug, or a new ferrule and service pipe can be fitted as required for a service relay or lead renewal. This solution was initially and continues to be developed with leading tier one contractors and Sarco Stopper to eliminate shut offs during the extensive AMP5/6 lead replacement programmes, where many hundreds of thousands of lead service pipes are to be replaced.
As no mains shut off is required for this solution, the following cost savings can be noted:
- No planning costs to assess the impact and cost of customer supply interruptions
- No valve operating risk assessment required
- No enabling works to mitigate stuck or broken valves
- No line stops to minimize impact of valve shut offs
- No on site valve operation, drain down and recharge costs
- No customer card warning or compensation costs
- No out of hours working, overtime costs or working in a less safe environment
- No risk of knock on bursts on recharge, discolouration or contamination incidents
- No risk of customer contacts to call centres or DG7 letters of complaint.
- No future leakage risk from old capped ferrules.
The BSI pressure certified and patent pending Arctic Driver®: Under Pressure Ferrule Extraction System is also applicable to a range of day to day network activities such as disconnections, service pipe renewals, pressure and flow complaints and all manner of supply pipe leakage jobs.