A tried and true method for trenchless rehabilitation of existing pipelines, sliplining can be a fast, economical option to repair leaks or restore structural stability to an existing pipeline... especially when capacity is not an issue.
During this process first undertaken in the 1940s, a smaller sized high density polyethylene (HDPE) or other carrier pipe is butt fused together and inserted into an existing host pipeline. Using a cable and winch system, the new liner pipe can be pulled into place. Or, using a choker cable and backhoe, it can be pushed into place. When conditions warrant, both methods can be undertaken together.
After the relaxation period, end restraints are installed at the ends of the HDPE pipe in the manhole. These end restraints prevent future creep of the HDPE pipe out of the manholes. Water activated expanding grout and oakum are installed in the annular space to prevent leakage.
When the new liner is in place, all service connections are reinstated with electro-fusion bonded watertight saddle connections.
KRG Utility recommends rehabilitating or replacing manholes as part of sliplining operations.
Sliplining can be an economical alternative to replacing culverts under roadways and pipes running through dams. HDPE and PVC pipe are the most commonly used materials for this process. Once the existing pipes are sliplined the annular space is normally grouted with a cementitious type of grout.