Uponor has been working closely with National Grid, the North West Gas Alliance, contractor May Gurney and equipment supplier TT UK Ltd, to trial the use of 110mm ProFuse pipe for pipebursting 4” iron mains using the TT Rollerblade pipebursting system with reduced diameter bursting head.

National Grid’s current recommendation for pipebursting with PE pipe is that the minimum PE pipe wall thickness to be used is 11.5mm, limiting the use of this technique to pipe diameters of 125mm SDR11 and above.

The use of ProFuse with its external skin has demonstrated that it is possible to pipeburst 4” iron mains with 110mm ProFuse, whilst minimising or eliminating damage to the ProFuse core pipe.

110mm ProFuse offers a bore for bore replacement of 4” iron mains, while the combination of the TT Rollerblade cutting head and reduced diameter bursting head has demonstrated that it is possible to use the pipebursting technique whilst minimising ground movement and without damaging the existing infrastructure.

The success of the North West Gas Alliance trials has led National Grid to approve the use of 110mm ProFuse for pipebursting applications.

A total of 14 pipebursting operations have taken place on six sites so far, and tests carried out by the University of East London to analyse ProFuse samples from all these pipebursting schemes have shown no damage to the ProFuse pipe and only superficial damage to the peelable outer skin in 1115 metres of tested pipe.

Mark Hunter is Uponor’s applications manager for gas distribution systems: “The purpose of these trials was to confirm the suitability of 110mm ProFuse pipe for pipebursting applications; its outer skin offers a high resistance to external scoring.”