April 2014— Accu-Freeze was used by a mechanical contractor in Montreal to perform a freeze seal on a 12” water main in the boiler room of the CBC Building in downtown Montreal. A freeze seal, or “ice plug” was required in order to change out an old valve that was seized up without having to shut down or drain out the system. They decided to contact COB Industries in order to purchase Accu-Freeze® equipment and to receive training to prepare them to tackle a critical job of this nature. In addition, they hired COB to provide a pipe freezing specialist to be on hand as a consultant while the job was carried out. The job was scheduled for the third week in April.
After a one-day Accu-Freeze® training session with COB, the freeze seal was performed at the CBC building. An ice plug was achieved in approximately 6 hours in spite of moderate vibration caused by a nearby pump (vibration causes turbulence in the water inside the pipe which impedes the freezing process). Once the presence of ice plug was confirmed the old valve was disassembled and removed and the new valve was hoisted into position and attached. The valve replacement took approximately 2 hours and the ice plug was maintained throughout the process. Once the new valve was in place, the Accu-Freeze® equipment was removed, and within 2 – 3 hours the plug had thawed and the system was fully operational again.
COB Industries has been manufacturing Qwik-Freezer® (portable CO2 Pipe Freezing Kits) for over 45 years and the patented Accu-Freeze® LN2 Freeze Systems for 20 years. Accu-Freeze® is a digitally controlled Liquid Nitrogen Pipe Freezing system that automates the LN2 injections and provides the ability to control the pipe wall temperature throughout the freeze seal process. Accu-Freeze® is in use worldwide at power generating facilities, power plants, at US Navy shipyards and by mechanical contractors and building maintenance personnel in many countries.