The process for an in-building pipe rehabilitation project
Preparation for this process starts with shutting off the water to the area being worked on and then gaining access to each stack line from the top floor. A temporary bypass system, involving the horizontal main sewer pipe located in the building’s basement, is installed to allow the crew to flush, clean, and repair the pipes. The bypass is then removed at the end of each day to restore full service to the entire building. This process is repeated each day as the crew moves through the building, restoring the pipes. Debris and blockage caused from years of build-up inside the pipes is then removed and cleaned using precision, high-speed drain cleaning tools to prepare the pipes for relining.
There are several non-invasive in-building pipe repair options which are significantly less expensive than total replacement costs. The most common methods of in-building pipe rehabilitation are brushed-in-place-pipe (BIPP) and cured-in-place-pipe (CIPP) processes. Ultimately, the diameter and condition of the pipes determine which method is used.
The BIPP process
The BIPP process requires specialty equipment to apply a 100 percent solids epoxy onto the interior walls of the pipe. Since epoxies are both highly corrosion- and abrasion-resistant, the relined pipe will function as new for many years. This method is particularly effective in leaking smaller diameter 31.75 to 203.2 mm (1.25 to 8 in.) drain and branch lines found in traditional plumbing. It can also be used to reline potable water mains, using NSF-61 certified, 100 percent solids epoxy.
The CIPP process
The CIPP lining process consists of a felt or fiberglass liner, pre-impregnated with epoxy resin that is inverted into the pipe. For a commercial building’s stack and vent lines, this is typically performed from the roof, all the way down into the basement. The CIPP liner is then cured; and depending on the system, it is cured either using water and steam or ultraviolet (UV) light. Once the liner is cured, the branch line connections from each floor are reinstated using a lateral reinstatement robot that cuts through the liner and seals
the connection.
Whether they be for sanitary sewer or drinking water applications. The products must show proof of meeting minimum ASTM standards, as well as NSF-61 drinking water safety standards.
