Pipe lining systems are offered as a trenchless, less disruptive option to a conventional sewer pipe replacement. Lining systems use the existing pipe as a mold and outside structure for the liners. Several types of pipe lining approaches currently are available, but all use epoxy resins cured within the old sewer, limiting the mess and expense of digging up yards, sidewalks, and streets. Each option is installed somewhat differently but all result in a new epoxy pipe being installed within the existing pipe.
Spray On Epoxy Pipe Lining
This method works best in pipes that are in reasonably good condition and larger than 2 inches in diameter.
A thorough jet washing of the pipe is done to remove debris to aid in a smooth and tight fitting coating.
The thick epoxy solution is sprayed on the inside of the existing pipe using a robotic mechanism.
The integrity of the coating is viewed using in-pipe remote camera technology.
Prior to use the epoxy coating is permitted to cure.
Cured In Place Pipe Lining
The cured in place method involves inserting a flexible epoxy saturated tube of fiberglass or other durable fiber into the existing sewer pipe.
Once inserted the contractor then uses hot steam or air pressure open up the sleeve within the pipe to adhere the epoxy and fabric sleeve firmly to the interior of the damaged line.
After the sleeve is installed correctly and it fits tightly within the old pipe it is allowed to cure or solidify in place.
Post-curing the pipe lining permits a smooth and unencumbered water and waste flow.
This method requires two access points.
Pull In Place Pipe Lining
Pull in place Pipe lining is a variant of the cured in place pipe lining, needing the two access points.
A cable is first strung through the pipe to be lined.
That cable is then attached to the pull in place liner, crafted of epoxy saturated fabric.
When the liner is in place between the two access points it is inflated using static pressure, ensuring it is molded tightly into the existing pipe.
The liner is then cured with water or steam after both ends are sealed for this step in the process.
Some contractors use an ultraviolet light moved slowly through the lined pipe to cure it.
Inversion Pipe Lining
Inversion pipe lining uses an added step that turns the epoxy saturated liner inside out within the existing pipe. This moderates drag and damage on the liner as it is inserted.
A special machine inserts the liner into one end of the pipe and uses strong air pressure to invert the sleeve into the pipe.
The process unrolls the sleeve inside out into the pipe without the need of a pre-inserted cable.
A calibration tube is inserted into the length of the inverted sleeve once the inversion is completed.
The calibration tube is expanded when either heated water is circulated or pressurized air is forced inside.
The expansion fits the sleeve tightly within the existing pipe.
The inverted sleeve is cured within the pipe before use.
This technique does not require more than one access point.