Freeze sealing pipes for repair or maintenance is an increasingly popular alternative to ‘hot-tapping’ as it eliminates the need to shut or drain down a system for repairs and maintenance. These systems work by creating ice plugs (or ‘freeze seals’) either upstream of the repair site or on either side of an area where a pipe system needs to be maintained.
The Pipestoppers® Division at Huntingdon Fusion Techniques HFT® manufactures Qwik-Freezer™, the industry standard portable CO2 Pipe Freezing System. Qwik-Freezer covers pipe diameters from 9 – 200 mm.
Qwik-Freezer requires almost no set-up time and is the only CO2 Pipe Freezing System capable of freezing up to 8 in. pipe. Even for smaller diameter freezes, Qwik-Freezer produces ice plugs that are capable of withstanding far more pressure than the smaller plugs that other types of systems will produce.
Georgia Gascoyne, CEO for Huntingdon Fusion Techniques, said: “Qwik-Freezer has become the preferred solution for a very wide range of water-carrying pipework, where valves need to be changed, in industry sectors such as: petrochemical, building and maintenance services, food and beverage, hospitals, water treatment, shipping and aerospace.”
A specially designed flexible jacket is wrapped around the pipe at the point where the freeze is required. A nozzle in the jacket is then coupled to a cylinder of liquid carbon dioxide by means of a high-pressure hose.
When the CO2 is injected into the space between the jacket and the pipe, at a temperature of -78°C, the pipe contents freeze and a secure ‘ice plug’ is formed, which seals the pipe. The ‘ice plug’ forms only in a section of the pipe covered by the jacket, so the resulting rise in pressure is very small and there is no damage to the pipe. The technique can be used safely on iron, lead, stainless steel, copper, brass and plastic pipe.
Edited from press release by Angharad Lock