News
Linergrip Guards Against Leaks
Posted on 01st Feb 2006
Viking Johnson's LinerGrip PE liner termination has provided a 'no-leak' solution for a re-lined water main in Haarlem, Netherlands
The 980mm diameter pipeline carries treated water for Amsterdam beneath Haarlem's historic central area, where excavations in the narrow streets had to be kept to a minimum.
Contractor Nelis Infra bv carried out the rehabilitation for the Municipality of Amsterdam Water Supply Company through just 12 excavation points along the 2.5km route by using the Subline® close-fit polyethylene lining technique.
The sections of the main and the 19mm-thick PE liner were re-connected with LinerGrips, which were designed specifically to ensure security of connection for mains rehabilitated with a PE liner - especially important in the case of thin-wall liners that are not self-supporting in the as-buried condition but rely on the strength of the host main for pressure retention.
As well as providing flanged connections at both ends of each re-lined section for other equipment and/or a make-up piece, LinerGrip has an in-built gripping arrangement to hold the PE liner and prevent it retracting inside the host main due to changes in temperature or the Poissons Effect when the PE liner is pressurised.
It also provides support for the liner, preventing damage by the shear forces arising as it emerges from the host main; and it 'seals back' onto the outside of the host, stabilising the entire fitting and preventing the ingress of ground water into the annulus between host and liner pipes.
