Pipe Freeze Time

bishop pipefreezing services ltd based in UK did a number of pipe frezzing job . for us few years back. coolant used was nitorgen at minus 196C. in their presentation, they cited several factors that affect the time/plug formation such as the ambient temp, pipe wall thickness, heat sink, integrity of the seals between the pipe and the jacket and convection within the pipe. Freezing time can vary between 4-18 hours.

you may want to check out the article featured in pipingdesign.com regarding pipefreezing technique

Several national leak repair companies in the US offer line freezing services. Check out the services of Koppl, Team Inc., and Furmanite. We have done this occasionaly using one of these companies. It is also possible to freeze pipe on your own but I wouldn't recommend it. Good luck.