A £7 million investment programme by United Utilities is renewing a 44-inch cast iron water main using polyethylene pipe from GPS PE Pipe Systems, according to newswiretoday.com.
A section of the main, running 4.4km from the M57 junction in Prescot into Liverpool, has suffered two bursts in recent times, resulting in flooding of houses in Huyton. In order to prevent further incidents the existing Victorian pipe is being slip-lined with 1000mm diameter PE100 (Excel) pipe manufactured at the GPS extrusion site in Huntingdon, Cambridgeshire.
Contractor Morgan Est is performing the installation, which began in November 2008 and is due to be completed in September 2009. Straight pipe sections are jointed using a 1m fusion welding machine that is unique in the UK. Welded pipe strings of 540m and of 570m have already been pulled into place and a second 540m length is in progress.
With a very small annulus between the close-fit ductile iron and PE pipes, grouting is not required, as the new PE lining is structurally supported by the host pipe. Consequently, substantial project savings are being made by using a SDR 21 specification, rather than a thicker-walled pipe. The thinner pipe wall also confers greater carrying capacity to the pipeline.
A key benefit of renewing the main by slip-lining is the avoidance of open-cut replacement and the major disruption that would be caused to traffic along the route. Welding pits at both ends of each relined section are just 15m wide, allowing one lane of the dual carriageway to be kept open in each direction.
GPS PE Pipe Systems (gpsuk.com) specialises in the design, development, manufacture and marketing of polyethylene pipe systems for the gas, water, sewerage and industrial markets. Many of the GPS product brands are widely used in pipeline installation, repair and maintenance and have a long record of integrity and innovation in meeting the needs of the gas and water utilities. Manufactured in the UK, our products are sold to more than 60 countries worldwide.