2022 Port Moody Sept 12 Inverted CIPP Liner

2022 PortMoody September 12

On September 12 , 2022, Insituform started to line the existing sanitary sewer lines that go through the Old Orchard Park. Insituform® CIPP is a cured in place pipe liner that is installed via air pressure. This is not a new experimental process and has been used for 5 decades and the life of 25,000 miles of pipe worldwide has been extended via the Insituform® CIPP.

The process had started months earlier with PW Trenchless Construction installing a sewer by-pass system to ensure the forcemain sewer main would be dry for the lining process and any flows of the sewer would be maintained while the process was proceeding. Entrance and exit pits were excavated and sored and fenced off to ensure the safety of the public on these well used trails. Although the first sewers to be relined were gravity mains, and the bypass system was not needed for the gravity lines, the lining process did not start till all the bypass system was in place, and all excavations completed.

The starting date for the Edmonton based Insituform crew, was a dry sunny day that had followed an unusually long dry period for the Lower mainland area of British Columbia. The crew showed up and the first process, was the obligatory wheel washing process to ensure no contamination into the parks eco-system. The Insituform crew did a camera inspection of the line, and they could send up a cleaning wand if needed.

 Once inspected, the truck which controls the lining system was put in place by the entry point at an existing manhole. At both the entry point manhole and the exit point manhole, a pipe testing plug was installed into the pipes entering the manhole that were not part of the lining process that day. This ensure no stray debris enter the “Host” pipe, the pipe that is to be lined.

The truck holding the liner is set up in place and the new liner has been “wetted” and needs to be kept cool with bags of ice surrounding the pipe supply. The liner is a Poly sleeve that has a felt inner membrane that is impregnated with a fiberglass type resin and pulled through a series of rollers at a specific height to ensure the whole membrane has an equal and proper amount of resin throughout the length of the liner.

A pipe liner inverter is set up over the entrance manhole and the liner is fed trough the inverter and the end is inverted, and held in place with steel bands. High pressure air is inverted into the plenum of the inverter to force the liner downwards into the entrance manhole and it is redirected by a wedge in the invert of the manhole that directs the liner towards the pipe to be lined.

As the air continues to be forced into the inverter, a liquid lubricant is applied to the “pipe Inverter” to allow the new liner to be installed with the minimum of friction and no damage to the liner. While the lubricant was added and poly tub was placed on the ground to make sure if any liquid dripped out it would be captured and not allowed to impregnate the ground of the park.

As the liner is inverted into the host pipe, the resin impregnated felt inner part of the liner inverted and is forced against the inside of the host pipe. It is not dragged along but rather is installed from the inside out and goes all the way to the exit manhole where it is guided out of the manhole via wood wedges that force it up and out of the manhole.

Once the liner was installed throughout the host pipe, a sleeve made of PVC pipe, the same diameter of the host pipe is placed around the excess liner on the ground out side of the exit manhole. This is marked with the date and batch number of both the liner material and the resin to provide a test sample of the liner.

The end of the installed liner is tied off and a small hole is drilled into the liner and a steel manifold pipe is inserted into the hole as a port to let the pressurised air escape. This steel pipe has a pressure guage along with a valve to allow the pressure to build up and keep a constant pressure to keep the liner mated closely with the host pipe. Once pressurized, steam is introduced to start the curing process. Temperature probes are carefully monitored to ensure critically important constant and even curing times and temperatures.

After a predetermined time, set by the length and diameters of the project, with a considerable safety margin, the steam is replaced by air and the pipe is cooled and then the pressure removed. The ends of the pipe are cut off and removed in sections to allow access to the manholes. After accessing the manholes the ends of the liners are carefully cut to correct shape of the host pipe as it enters the manhole.

Cleanup and removing of the excess is fast and careful, with all necessary means used to ensure no damage to the surrounding area or manholes.