San Francisco, California Cured in Place Vent Stack Lining
When faced with damaged vent stacks, most property owners opt to perform vent rehabilitation rather than replacement. Vent stack rehabilitation is only two-thirds the cost of replacement in San Francisco. This is because it needs less people on the job and there is no need to destroy any part of the property when doing the repair. Cured-in-place pipe (CIPP) is a pipe rehabilitation system that can be done on vent stacks. This system uses fiberglass liner that’s inserted into the broken pipe, which is then cured with ultraviolet light.
Since the ventilation is one of the most important parts of a building, only professional contractors should perform the lining process. A good team will clean all of the dirt or debris from the pipe before starting the repair. A computer-controller robotic camera will then be used to conduct a thorough inspection of the vents. The crew can then view the video footage from the ground level and handle any potential problems before the vent stack lining installation.
A pre-liner will be pulled through the pipe after the inspection and prep work has been completed. The contractors will then attach a winch cable which pulls the fiberglass liner through the vent pipe. The end gates, now secured with heavy duty nylon straps, will then be placed inside each end of the liner to pressurize it. The liner is then slowly inflated.
After the inflation, pressure will be reduced so that a 12-foot long train of 8 UV lights with a camera on the nose can be inserted in the upstream end of the liner through any of the end gates. The contractor will then attach a rope that has been manufactured inside the liner to the nose of the train before inserting it into the liner.
With the light train in place, the end gate can then be closed again and the pressure brought back to normal (8psi). To visually inspect the liner for any problems before it is cured, the light train will be pulled. If the vent stack is in good condition, the UV lights on the train will be lit as a machine pulls the light train back to monitor the entire curing process. This is an important device that controls the temperature, speed, and pressure of the entire curing process. The UV curing system usually needs one minute for every 4 to 8 feet of repaired pipe.
To finalize the process, contractors will remove the light train and end gates before they start trimming the liner ends. A cut will then be inserted and precision cuts made at each lateral to restore the service to the main.
Installing cured in place vent stack lining in San Francisco is the way to go. Property owners prefer this method since the breakdown of equipment is minimal. Time taken to complete the job is also minimized and the crew can be off the job and on to another one in a matter of minutes.