Sliplining a new liner pipe into a deteriorated host pipe provides the life span and benefits of a brand-new pipe with minimal construction cost and social impact, offering public works departments a way to maximize the value of an existing resource in a way that is less invasive to the neighborhood. In segmental sliplining, new factory-made pipe is pushed into place into existing deteriorated pipe, adding one segment at a time to the “train” to provide a new, corrosive-resistant, leak-free, long-term solution.
How do I decide if my existing deteriorated wastewater or sewer line is a good candidate for the sliplining rehabilitation method?
An accurate survey using a CCTV camera will show the extent of deterioration and other issues regarding the existing host pipe. The answers to these issues will determine the best method of rehabilitation:
- Shape of the host pipe: circular, non-circular
- Structural integrity of the existing line
- Condition, such as significant sagging, mineral deposits, cracks, etc.
- Foreign materials intruding into the host pipe, such as exposed rebar, hanging gaskets or roots
- Locations of extreme bends, curves, deflections, offset joints or undersized host pipes
- Distance that the liner pipe will have to be pushed
In addition to the survey, a hydraulic analysis will reveal flow characteristics in a gravity line or forced main, including the maximum flow and velocity during peak hours and in association with rain events. This additional information will help determine the optimal diameter of a liner or replacement pipe.
If the survey determines that segmental sliplining is a good option, what are my next considerations?
“The first consideration is what size liner pipe should be chosen. Liner size will affect not just constructability, but ultimately the sizing choice affects the capacity and hydraulics of the pipeline,” stated Kimberly Paggioli, P.E., vice president of marketing at Hobas Pipe USA.