Freeze Sealing for Pipe Repairs with Qwik-Freezer
03 Sep 2015
Freeze sealing pipes for repair or maintenance is an increasingly popular alternative to ‘hot-tapping’ and eliminates the need to shut down 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.
Qwik-Freezer®, which covers pipe diameters from 3/8” – 8” (9 – 200 mm), is the industry standard for portable CO2 Pipe Freezing Systems with thousands of kits in use around the world for over 40 years. Qwik-Freezer® is very quick and easy to use, requires almost no set-up time and is the only CO2 Pipe Freezing System capable of freezing up to 8” pipe. Even for smaller diameter freezes, Qwik-Freezer® produces ice plugs that are significantly more reliable and robust, capable of withstanding far more pressure than the smaller plugs that other types of systems will produce.
The diameter range of 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 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 -78OC, 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.
By not having to drain systems of liquids to make repairs, the savings made are able to justify the low relative cost of the Qwik-Freezer® System.