Frequently Asked Question

  • How does the N-TWO pipe freezing system work?
  • When a Pipe is in need of repair, Liquid Nitrogen is fed into a specially designed containment unit that isolates the area of the pipe in need of repair. This forms a secure ice plug which is maintained until repairs are complete.
  • Will the ice plug burst the pipe?
  • Ice always expands via the path of least resistance. Since only a portion of the pipe is frozen the ice plug has room to expand into the pipe on either side of itself.
  • How long does it take for the ice plug to form?
  • This depends greatly on the liquid contained in the pipe and the actual pipe diameter. The processes can take anywhere from 45 minutes to 10 hours.
  • How long will the ice plug last?
  • The ice plug is constantly maintained by our technicians and can last however long the repairs take, from 2 hour to several days.
  • How do you know when the ice plug has formed?
  • Our vast experience in the field along with mathematical calculations which take into account the diameter of the pipe, the type and temperature of the liquid within the pipe, and the material the pipe is made of, are used to gauge freezing times.
  • Is liquid nitrogen safe?
  • N-TWO Cryogenics had over 18 years experience handling and working with Liquid Nitrogen with a perfect safety record. Liquid nitrogen is 100% safe; in fact, 78% of the air we breathe is nitrogen.