CCT carryout liquid nitrogen pipefreezing on pipe diameters from 1/2" up to 24"

Pipefreezing is carried out by clamping a specially designed insulated 'jacket' around the pipework at the point to be isolated, providing an annular space between the pipe wall and the inner skin of the jacket.

Cryogenic refrigerant (liquid nitrogen) is then introduced into the annular space within the jacket, creating a bath around the pipe at cryogenic temperatures -196c.

As heat is exchanged between the pipe contents and the liquid nitrogen bath, the temperature of the contents is reduced to its freezing point, and an iceplug gradually forms within the pipe.

The liquid nitrogen gasifies, is vented off and replenished from a storage vessel. Once the iceplug is completly formed and tested under a pre agreed procedure, the pipe work modification or valve replacement can be carried out.

Provided the liquid nitrogen supply to the freezing jacket is constantly monitored and maintained, safe systems applied to monitor oxygen content at the work site, the iceplug can be maintained until the mechanical work is completed and the pipework made safe.

The iceplug is then thawed under a pre agreed CCT procedure.