Pipe freezing

If you are looking for a way to isolate your pipeline problem, Pipe freezing is a fast, clean and efficient method for carrying out repairs and piping alterations without having to isolate or drain an entire piping system.

Over the past 30 years, pipe freezing for temporary pipe isolation has become one of the safest, reliable and cost-effective methods for allowing valve replacement and general pipe work modifications.

Intero Integrity Services offer two effective pipe freezing solutions:

Direct liquid nitrogen pipe freezing

Direct liquid nitrogen pipe freezing is the most common procedure used to establish isolation on a pressurized pipeline. It requires the application of liquid nitrogen on to the external surface of the pipe. This transfers the low temperature liquid nitrogen through the pipe, reducing the pipe fluid to a temperature below its freezing point and developing the freeze plug.

This technology allows us to control the area of the pipe to be frozen. Once a plug has formed it is capable of withholding pressures up to 4000psi and this is maintained to allow pipe work modifications to be undertaken with confidence. Freeze time is dependent upon many factors, primarily the size of the pipe, although system conditions and ambient temperatures are also contributing factors. Once the particulars of an application are known, it is possible to predict an actual freezing time.

Indirect liquid nitrogen pipe freezing

Liquid nitrogen has a boiling point of -195.8°C (-384.4°F) and acts as a coolant in indirect pipe freezing systems. On pipe work compatible with cryogenic liquids, liquid nitrogen can be used as the direct cooling medium.

Intero Integrity Services’ pipe freezing approach provides a number of benefits over more conventional approaches:

  • Time savings due to the ‘no draining operation’
  • Cost savings as liquid waste is limited
  • Repairs can be carried out without interruptions to the process system
  • Provides isolation for pressure or leak testing
  • Effective use of plant/platform personnel
  • Avoids contact and handling of toxic or corrosive liquids.