Trenchless Pipe Rehabilitation: Why 45 °C Changes the Method

Chapters

Each chapter opens the video at that point on YouTube. Read the script under each chapter. From the subtitle track delivered with the video. Refer to the video and product documentation for technical details.

1. 010:00What a CCTV survey must record before a trenchless pipe repair

   Trenchless pipe rehabilitation starts with a clock. A resin patch has thirty-five minutes of working time at twenty degrees. At forty-five degrees, it has five. Every rehabilitation starts with a camera in the pipe. It records the measured bore at the defect, and the defect length and chainage. Then the groundwater head above the invert, and the opening the tool has to pass. Without those four numbers, every method looks possible. The defect itself decides the repair. A crack under a running leak needs a seal that holds immediately. A dry crack can wait for a patch to cure.

2. 020:35Why resin working time collapses in hot weather

   A point repair carries a resin patch on an inflatable packer. The packer presses the patch to the wall and holds it while the resin cures. Reliance publishes forty minutes of summer curing time. The packer is the same tool whether it carries a patch or expands a sleeve. It has to hold its pressure for the whole cure, and then come back out. Every method that depends on a cure depends on that time. Working time is chemistry, not site practice. Reaction rate rises with temperature, so the window closes faster. Thirty-five minutes at twenty degrees becomes five at forty-five.

3. 031:12How a mechanical repair sleeve locks without curing

   A mechanical sleeve does not wait for a cure. It goes in rolled around the packer, and unrolls against the wall. The locking gear catches, and the EPDM jacket is compressed onto the pipe. The packer leaves and the seal is already holding. The sleeve is a stainless shell with an EPDM jacket. Reliance builds it in 316L, with a pitting resistance number of twenty-three point five or more. Grade 304 sits near eighteen, and in warm chloride groundwater it pits through.

4. 041:43What to specify for a trenchless pipe rehabilitation

   A point repair is not the answer for a whole reach. When defects cover more than twenty percent of the run, the length gets a liner. Reliance supplies the point repair; the lining is a separate scope. So the method follows four measurements. The measured bore at the repair, not the nominal size. The defect length, plus seventy-five millimetres of sound pipe at each end. Above three metres of groundwater head, the landing goes to one hundred millimetres. And the access: can the tool reach the defect from that opening? The street above never closes, and the line goes back into service. That is the point of working from inside the pipe.