Cured In Place Pipe (CIPP) Lining
Cured In Place Pipe Lining Installed In Old Rusted Sewer Pipe
Cured in place pipe (CIPP) lining is a way of relining the inside of pipes using a long fabric tube which is typically made out of fiberglass or polyester. The long flexible tube is first wet out or saturated with a resin which is self-hardening by a chemical reaction, or heat is used to harden the resin. The heat is delivered through steam injection or hot water.
CIPP Is a New Physical Pipe
The new inner lining typically has a thickness from 3mm-6mm, which is as thick as regular modern plumbing pipe that would be used to physically replace pipes. The CIPP is designed to be a stand-alone, load bearing pipe in the event that there are missing pipe sections or the outside pipe deteriorates completely.
The Inner Diameter Is Only Reduced By 6%
A 3mm thick lining inside a 4″ pipe (104mm) means that the inner diameter is only reduced by 5.7%, which is insignificant for flow considerations.
100 Year Engineered Life
Although the pipe lining warranties range from 10-50 years, the actual engineered life of the pipe lining exceeds 100 years.
Installation – How It Works
First the problematic pipe is video inspected. Sometimes it is necessary to clean the pipes so that the camera leans is not obscured by debris. The video inspection is used to determine the length of the pipe lining required.
Pipe Liner Cut To Correct Length, Then Saturated With Epoxy Resin
Next the pipe lining material (“liner”) is cut to the correct length and the correct amount of resin is weighed out and mixed. The mixed resin is then used to completely wet out or saturate the “liner”, after which the liner is either pulled into the pipe by a cable that strung inside of it, or air is used to “shoot” (invert) the liner into the pipe. Inversion means that air or water is used to turn the liner inside out inside the pipe, like turning a sock inside out.
Then the liner is inflated under air pressure and held against the pipe walls where the resin hardens after about 3 hours. Finally the new pipe lining is video inspected for quality control.
What Happens To Pipe Connections?
Robotic Cutter Used To Open Pipe Connections That Are Covered Up By New Pipe Lining
When installing a continuous liner the connecting pipes are blocked off. Various proprietary methods are used to cut open these spots in the pipe lining so that flow can be restored. One such method utilizes a robotic cutter that is sent into the relined pipe, and with the aid of video coverage, the robotic cutter can cut out precise amounts of lining where the adjoining pipes connect. The disadvantage of this method is that it is very time consuming and thus increases cost of pipe lining installation.
Another method, used more frequently, is to make the pipe lining material “skip” over the connections. In essence, the pipe lining stops about 4″ before the pipe connection, and starts again about 4″ after the connection. So the area near the pipe connection remains unlined, which is the pipe fitting itself (like a wye or a “tee”), and these fittings are usually in much better shape than the pipe because they are about twice as thick. So this is the method generally employed when the pipes cannot be without flow for too long, like in hospitals and occupied high rise buildings.
