An Overview of Sliplining
Although sliplining is a trenchless service, it is not useful for all conditions. it is best used for straight piping projects.
There are many options to repair a damaged pipeline. Traditional trenching techniques allow workers to expose the line, remove it, and replace it with a new one. However, it can be costly and time-consuming. However, the trenchless option of sliplining may be a better choice. As one of the oldest, in use since the 1940s and most straightforward trenchless techniques, it is definitely one to consider.
Sliplining is when workers insert a pipe within a damaged pipeline. The new plumbing is made of either polyvinyl chloride (PVC) or polyurethane (HDPE or PE), with PE the most common choice. In many cases, the annular space between the new line and the original line gets filled with grout. The use of grout depends on how much space remains in between the two structures. The original plumbing helps to give additional structural support to the network as well as protection for the new line.
The new pipeline is a smaller diameter than the original line. However, this should not affect the overall flow of gas, sewage or water into the property. If there is damage to several sections of pipe, the sliplining procedure can be segmental with joints connecting the different segments of the line.
To insert the new line, technicians have different options available. They can use a pushing machine to get the pipe in place. Alternatively, an excavator may pull the lining through. Some companies prefer to use a winch, while others insert the new plumbing manually.
Repair personnel uses sliplining techniques to seal leaks in straight sections of plumbing. Also, the rehabilitation technique helps to restore structural integrity to the existing lines.
As sliplining uses hard pipe such as PVC, HDPE, and PE, it’ best use is in straight lines. Workers can connect sections of sliplining if necessary. All utilities including water, sewer and gas can use this technique for repairs. However, it is best-used in lines that do not require a large diameter for high flow as the smaller diameter pipe may cause problems. (Learn more in "Sliplining or Pipe Bursting for Pipe Repair?")
Unacceptable Sliplining Conditions
Even though repair specialists recommend sliplining for a wide array of repairs, there are some areas where this method just will not work.
Pipes with several bends are not good candidates for sliplining procedures. The hard material is not flexible enough to curve with the existing structure. Other pipe lining techniques, such as cured-in-place pipe, is a better alternative for this condition.
Lines that are excessively deteriorated or have protrusions or deformities do not work well with sliplining. Excessively deteriorated pipes do not have enough structural support to allow any pipelining option. Likewise, plumbing with protrusions or deformities makes it impossible to insert the new liner. For these pipelines, using a technique like a pipe bursting may be a better solution. (Read on in "An Introduction to Pipe Bursting.")
In terms of how much money sliplining procedures save, it helps to remember that this is a trenchless service. Workers will not need to dig up the existing lines to access the damage. That means sidewalks, driveways, and building foundations remain intact. Instead, they use a no-man access point to complete the project. Workers do not have to take lines out of service to complete the project. The method can save owners between $3,000 and $20,000 by not having to re-landscape or make additional repairs to concrete structures.
As some people measure the cost not only in monetary means but in the amount of time, a project takes, sliplining work completes in days versus weeks.
Sliplining does not work for all cases. However, it is the best option for the majority. Property owners needing pipeline repair may find that this method saves the time and money. A certified trenchless repair specialist can determine if this process works best for your situation.
Written by Denise Sullivan | Technical Writer @ Trenchlesspedia
Denise Sullivan is an accomplished freelance writer from Louisiana, with a Associate's Degree in Journalism from Eastern Oklahoma State College. She also graduated from East Central University with a Bachelor's in Biology. Denise began her writing career writing operations and maintenance manuals and software utility manuals for flight simulators. Since, she has expanded her writing to a broad spectrum of topics.