Pipe lining is a trenchless method used to repair broken pipes. The inside of a damaged pipe is lined with a new material which strengthens the pipe and provides a new,
water-tight inner-pipe for wastewater. Lining damaged pipes removes the need for large trenches. Pipes can be repaired faster and the work has much less impact on residents and traffic. But it won’t work everywhere. It is only suitable where the size of the wastewater pipes does not need to be increased or the grade of the pipes has not been affected by the earthquakes.

Whilst there are many different techniques used to line pipes, Fulton Hogan and Hydrotech are using a method called ‘fold and form PVC liner’ for the New Brighton wastewater pipes. A liner pipe is preheated in a warming trailer. This makes it flexible so it can be folded and pulled into the damaged pipe by a cable and winch. The pipe liner is then inflated and pushed against the inside of the existing pipe with steam where it sets in place.

A robotically-controlled cutting device goes through the lined pipe and cuts out holes in the lining where the laterals are connected to the main. These connections are then sealed again.

For more information see:
http://strongerchristchurch.govt.nz/article/finding-your-inner-pipeline-in-new-brighton