Crucial maintenance through pipe freezing
The system is available from the Pipestopper Division of Huntingdon Fusion Techniques HFT.
Georgia Gascoyne, CEO of HFT, said: “Pipe freezing is a simple and efficient way of sealing a pipe or system while pipe repairs or general pipework maintenance is carried out, without the need to drain the system.”
Accu-Freeze works by reducing the pipe fluid to a temperature below its freezing point and developing a freeze plug. This controlled method of pipe freezing uses liquid nitrogen (LN2) to freeze stationary liquids in a section of pipe or tubing.
The nitrogen is passed through a coil surrounding the pipe producing a frozen plug inside and hence preventing flow through the part to be removed.
The ice plug only forms beneath the Accu-Freeze coil wrap, jacket or aluminium clam jacket. The system is effective on 6–12in (150 to 300 mm) pipe or tube. The ice plug does not expand outside of the range of the jacket or coil.
The LN2 injections are automated which reduces the operators’ workload and the amount of LN2 consumed, keeping operating costs low. Accu-Freeze can also be operated remotely, which makes it ideal for use inside ‘hot’ nuclear areas where personal exposure must be kept below certain limits.